Build to Sell vs Build to Hold: Complete Guide for Australian Developers

For most property developers in Australia, the default strategy is straightforward: acquire land, secure approvals, construct, sell everything, and move on to the next project. But an increasing number of developers are now asking a different question—should I hold some (or all) of the completed stock instead of selling?

This decision may seem simple on the surface, but it fundamentally changes almost everything about a development project: the funding structure, GST treatment, valuation methodology, lending criteria, and long-term financial modelling. The Australian Prudential Regulation Authority (APRA) has specifically flagged “construct to hold” residential development loans as an emerging risk category, noting these loans “imply higher credit risk” than traditional presale-backed development finance.

This comprehensive guide breaks down the real differences between Build to Sell (BTS) and Build to Hold (BTH)—including funding, GST, valuation methods, feasibility modelling, refinance risk, and the software tools you may need for each strategy. Whether you’re planning to retain one unit, transition into institutional Build-to-Rent (BTR), or run a hybrid strategy, understanding the shift from development to investment is typically considered critical for success.

Development vs Investment: Two Fundamentally Different Businesses

The moment you decide to hold completed stock rather than sell it, you’ve stopped operating as a developer and started operating as an investor. This isn’t merely a philosophical distinction—it changes how lenders, valuers, and the Australian Taxation Office (ATO) view your project.

Build to Sell: The Development Model

A traditional development feasibility typically assumes all lots or units will be sold upon completion. The funding structure is built around:

• Cost to complete (total development costs)
• Gross Realised Value (GRV) based on comparable sales
• Completion dates and construction programme
• Presale contracts to de-risk senior debt
• Settlement proceeds repaying construction finance

Banks lending for development projects focus primarily on the GRV and your ability to achieve presales. The security is the project itself, and repayment comes from sales settlements. This model has clear entry and exit points—capital goes in, completed product comes out, profit (or loss) is realised, and you move on.

Build to Hold: The Investment Model

Once you retain completed stock, the financial logic shifts entirely. Investment lending is driven by:

• Net Operating Income (NOI) from rental returns
• Debt Service Coverage Ratio (DSCR), typically 1.2x to 1.5x minimum
• Long-term cashflow projections
• Yield and capitalisation rate valuations
• Personal or entity serviceability for refinanced debt

The Reserve Bank of Australia’s financial stability reviews consistently highlight that investment property lending operates under different risk parameters than development finance. Your exit becomes either indefinite hold, portfolio sale, or eventual individual sales—none of which have the clean timeline of a development project.

This fundamental shift is why feasibility tools, lending requirements, and tax treatment change so dramatically between the two strategies.

GST and the Margin Scheme: The Critical Trap Developers Overlook

Perhaps no area creates more unexpected liability for developers than the GST implications of changing from a sell strategy to a hold strategy. The ATO’s guidance on the margin scheme is clear: it only applies to property that is sold.

How the Margin Scheme Works

Under the margin scheme, GST is calculated on the margin (the difference between the sale price and the original purchase price) rather than the full sale price. For developers who acquired land from non-GST-registered vendors—common when buying from private landowners—this can significantly reduce the GST liability on completed sales.

However, there’s a critical catch that many developers miss: the margin scheme benefit is claimed at acquisition but only crystallises upon sale. If you apply the margin scheme when purchasing land with the intention to sell all units, then later decide to retain some units, the ATO may claw back the margin scheme benefit for the retained lots.

A Worked Example

Consider a developer who plans to build and sell 10 townhouses:

• Land purchased for $2,000,000 (margin scheme applied)
• Total GRV of $8,000,000 ($800,000 per townhouse)
• Market shifts, developer decides to keep 2 townhouses

Under Division 129 of the GST Act, the developer may face an adjustment. The margin scheme benefit claimed for those 2 retained lots could be required to be repaid. The effective additional GST hit is typically around 3% of the property value per retained lot—in this example, potentially $48,000 in unexpected GST liability.

This adjustment can be assessed years after completion, catching developers off guard long after they’ve moved on mentally from the project.

Joint Ventures and GST Complexity

The GST position becomes even more complex in joint venture arrangements. If a landowner contributes land and receives a completed dwelling as consideration (rather than cash), the margin scheme may not apply at all. The ATO’s ruling on property development joint ventures provides guidance, but the interactions between GST, income tax, and property transactions in JV structures typically require specialist accounting and legal advice.

Key principle: If there is any possibility you may retain stock—even as a contingency—the GST treatment must be considered and documented upfront. Retrospective changes to intention carry significant compliance risk.

Funding Structures: Three Standard Approaches

The funding structure you choose is typically one of the biggest determinants of which exit strategy remains viable. Understanding how lenders view different structures helps you maintain flexibility without triggering covenant breaches or refinance failures.

Standard Build to Sell: Development Finance

The traditional development funding stack looks like this:

The feasibility model assumes all lots are sold, there’s no long-term debt to service, and no rental income considerations. This is what most senior lenders expect, and it’s the structure that attracts the most competitive interest rates.

Major banks including NAB, CBA, Westpac, and ANZ all offer development finance, though appetite and terms vary significantly based on project type, location, and developer track record.

Full Build to Rent: Institutional Investment Structure

When a developer intends to retain the entire building as an income-producing asset, the funding structure changes fundamentally:

The key differences are substantial. Banks lend against projected Net Operating Income rather than GRV. Valuations are based on capitalisation rates rather than comparable sales. Internal Rate of Return (IRR) and DSCR metrics matter more than development margin. The exit strategy is either hold indefinitely or sell the entire income-producing asset to an institutional buyer.

Qualitas recently launched Australia’s first dedicated Build-to-Rent debt platform—a $1 billion fund offering 7-year loans at up to 70% LVR, specifically designed for this asset class. Traditional banks remain more conservative, typically at 50-55% LVR for BTR projects.

Hybrid Strategy: Sell Some, Hold Some

The hybrid approach is arguably the most common for small to medium developers, but also the most complex to structure correctly.

The typical stack involves:

• Standard development finance during construction
• At completion, sales proceeds pay down construction debt
• Retained stock is refinanced individually onto investment loans
• Developer equity shifts from development to investment position

Lenders typically require early disclosure of any intention to retain stock. You’ll need individual valuations on each retained lot, rental appraisals from registered valuers, serviceability evidence (personal or entity), and may still need to meet minimum presale or GRV coverage ratios.

This structure provides flexibility but requires sophisticated feasibility planning. The development feasibility and the investment feasibility need to work together—a shortfall in either can unravel the entire project.

How Banks Assess Build to Sell vs Build to Hold

Understanding how lenders evaluate these different strategies helps you structure projects that remain financeable throughout their lifecycle.

Development Lending Assessment (Build to Sell)

When assessing a traditional development loan, banks focus on:

The Australian Banking Association’s guidance on responsible lending influences how banks approach development finance, though specific policies vary by institution.

Investment Lending Assessment (Build to Hold)

For held stock or BTR projects, the assessment framework shifts dramatically:

The developer must prove the completed asset can service its long-term debt—not just that it’s worth enough to cover the loan if sold.

APRA’s Specific Concerns About Construct-to-Hold

In a 2024 speech on commercial real estate lending, APRA explicitly flagged construct-to-hold residential loans:

“APRA has observed an emergence of ‘construct to hold’ residential development loans which do not require, or require reduced levels of, qualifying pre-sales. All else being equal, these loans imply higher credit risk.”

This regulatory attention suggests banks may become more cautious about hybrid or hold strategies, particularly for developers without substantial track records in investment property management.

Valuation Methodologies: GRV vs Income Capitalisation

The valuation approach fundamentally differs between sell and hold strategies, and this difference can create significant gaps between what you think a project is worth and what a bank will lend against.

Gross Realised Value (Build to Sell)

GRV valuations are based on comparable sales—what similar completed properties have sold for in the relevant market. The valuer analyses recent transactions, adjusts for differences in size, quality, and location, and arrives at an estimated sale price for each lot.

From GRV, you subtract total development costs to arrive at your development margin. This is the standard approach for all development feasibilities and what banks use to determine maximum loan amounts.

Key vulnerability: GRV is entirely market-dependent. If comparable sales decline during your construction period, your GRV falls, potentially triggering covenant issues or requiring additional equity.

Income Capitalisation (Build to Hold)

For investment properties, valuers use the income capitalisation approach:

Value = Net Operating Income ÷ Capitalisation Rate

For example:

• Annual rental income: $600,000
• Operating expenses: $100,000
• NOI: $500,000
• Cap rate: 5%
• Valuation: $10,000,000

The critical sensitivity here is the cap rate. If cap rates expand (increase) due to rising interest rates or market uncertainty, values fall—potentially dramatically:

A 100 basis point cap rate expansion reduces value by over 16%. This cap rate sensitivity is one of the most significant risks in build-to-hold strategies.

The Australian Property Institute’s valuation standards provide guidance on when each methodology is appropriate and how they should be applied.

The Valuation Gap in Hybrid Strategies

When you sell some units and hold others, you may face different valuations for the same underlying asset. York Finance notes that bulk or retained stock valuations often attract a 15-25% discount compared to individual sale valuations. This discount reflects the illiquidity and holding costs associated with unsold stock.

Understanding this valuation gap is critical when modelling hybrid strategies—the retained units may be worth significantly less on paper than their theoretical individual sale prices.

Changing Your Intention Mid-Project

Market conditions change. A hot pre-sale market can cool. Interest rates move. What happens when you need to pivot from one strategy to another?

What Changes When Intention Shifts

Changing from Build to Sell to Build to Hold mid-project affects virtually every aspect:

How the ATO Assesses Intention

The ATO considers multiple factors when determining original intention:

• Documentation at the time of acquisition
• Feasibility studies and their assumptions
• Presale strategy and marketing materials
• Ownership structure and stated purposes
• Board minutes or investment committee papers
• Statements made to lenders and valuers

Tax Determination TD 92/126 addresses situations where a developer changes intention due to market conditions. While the ATO acknowledges that genuine changes in circumstances can justify a change of intention, the burden of proof rests with the taxpayer.

If you anticipate any possibility of holding stock, documenting this contingency from the outset—even if sell remains the primary intention—provides significantly better protection than trying to justify a change retrospectively.

Development Feasibility vs Investment Feasibility

A common mistake is trying to combine development and investment analysis into a single model. The logic, metrics, and timeframes are fundamentally different—they require separate feasibilities that interact but don’t merge.

Development Feasibility (Build to Sell)

A standard development feasibility includes:

• Total Development Cost (TDC) breakdown
• Gross Realised Value (GRV)
• GST calculations including margin scheme
• Construction interest (capitalised)
• Development margin percentage
• Return on Cost (ROC)
• Cashflow to Practical Completion
• Funding waterfall (land settlement through sales settlement)
• Sensitivity analysis on GRV and costs

Investment Feasibility (Build to Hold)

A hold or BTR feasibility requires entirely different modelling:

• Rental income projections (10-30 years)
• Operating expenses including management fees
• Repairs and maintenance provisions
• Capital expenditure forecasting
• Vacancy and incentive allowances
• DSCR calculations
• IRR, NPV, and equity multiple analysis
• Terminal value (exit cap rate)
• Refinance assumptions and timing

These two feasibilities need to be run separately, then reconciled at the point of completion where the development phase ends and the investment phase begins.

Software Tools: Matching Your Toolset to Your Strategy

Build to Sell and Build to Hold are not just different exit strategies—they are fundamentally different financial models requiring different lending structures, different tax treatments, and different valuation methodologies. The software you use should reflect this distinction.

Development Phase: Feasibility to Practical Completion

For the development phase through to practical completion, developers need tools purpose-built for development logic:

• Development cost modelling and TDC tracking
• Funding stack structures with debt/equity waterfalls
• GST and margin scheme calculations
• Construction cashflow and interest capitalisation
• GRV-based sensitivity analysis
• Scenario comparison across different development approaches

Feasly is designed specifically for this phase—providing Australian developers with reliable, structured, user-friendly feasibility modelling from land acquisition through to completion. Feasly handles the complexity of funding stacks, GST scenarios, and development-specific cashflows that generic spreadsheets struggle with.

Investment Phase: Long-Term Asset Management

Once a project transitions to a long-term rental asset, the analytical requirements change completely. Investment modelling tools need to handle:

• Long-term rental income projections (10-30 years)
• NOI and DSCR calculations
• IRR, NPV, and equity multiple analysis
• Cap rate sensitivity and terminal value modelling
• Refinance scenario planning and debt structuring

Dedicated investment analysis tools, property portfolio software, or sophisticated financial modelling platforms are better suited to this ongoing asset management phase. The metrics, timeframes, and reporting requirements differ substantially from development feasibility.

Why Separation Matters

By keeping development logic separate from investment logic, developers avoid:

• GST traps: Margin scheme adjustments that catch developers years after completion
• Refinance failures: Unrealistic assumptions about post-completion lending
• Incorrect feasibilities: Blending development margins with investment returns in ways that obscure true performance
• Costly surprises: Operating costs and cap rate sensitivity overlooked until it’s too late

The transition point—practical completion—is where development feasibility ends and investment feasibility begins. Using the right tool for each phase ensures both analyses are robust and fit for purpose.

Operating Costs: What Developers Often Underestimate

Developers accustomed to the sell model frequently underestimate ongoing operating costs when modelling hold scenarios. These costs directly impact NOI, DSCR, and long-term viability.

Typical Operating Expense Categories

Land Tax Implications

Land tax is a significant ongoing cost that varies dramatically by state and ownership structure. Each state has different thresholds, rates, and surcharges:

• NSW: Land tax applies above $1,066,000 threshold (2024-25), with rates from 1.6% to 2% plus surcharges for foreign owners
• Victoria: Threshold of $50,000, with rates up to 2.25%
• Queensland: Threshold of $750,000 for individuals, lower for companies and trusts
• Western Australia: Threshold of $300,000, rates up to 2.67%

The NSW Revenue Office, State Revenue Office Victoria, Queensland Revenue Office, and other state revenue authorities provide current rates and thresholds.

The Vacancy Reality

Many developers model 0% vacancy for hold scenarios—an unrealistic assumption that can materially overstate returns. Industry standard is typically 5% vacancy allowance, but this may be conservative in softer rental markets or for properties requiring tenant turnover.

Leasing incentives (rent-free periods, fit-out contributions) are also commonly overlooked. In competitive rental markets, 2-4 weeks of incentive per lease renewal is not uncommon, effectively increasing vacancy impact.

Lease-Up Period: The BTR Reality Check

One of the most misunderstood aspects of Build to Rent is the stabilisation period—the time between practical completion and achieving stabilised occupancy.

Typical Stabilisation Timeframes

For purpose-built rental developments:

• Small developments (10-30 units): 3-6 months
• Medium developments (30-100 units): 6-12 months
• Large developments (100+ units): 12-18 months

During this period, the asset is not generating its full income potential, but debt is already in place. This creates a funding gap that requires specific financing solutions.

Stabilisation Finance

Banks typically offer stabilisation facilities that bridge the gap between construction loan expiry and investment loan conversion. These facilities:

• Run 6-18 months depending on project scale
• Carry higher interest rates than permanent debt
• May require interest reserves or additional security
• Convert to term debt once occupancy targets are met

The cost of this stabilisation period must be factored into hold feasibilities—it’s effectively additional development cost that erodes investment returns.

Incentives and Market Building Costs

New developments entering the rental market often require incentives to attract tenants:

• Reduced rent for initial lease period
• Rent-free weeks
• Moving cost contributions
• Furniture packages

These incentives reduce effective rental income during the critical early period and should be explicitly modelled rather than absorbed into vague “marketing” allowances.

Refinance Risk: The Silent Killer

Perhaps the most underestimated risk in Build to Hold strategies is refinance failure. Many developers assume they can simply refinance construction debt into permanent investment debt at completion. This assumption often proves incorrect.

Why Refinance Fails

Banks assess refinance applications based on:

• DSCR at current (not original) interest rates
• Interest rate buffers (typically 2-3% above market)
• Current valuations (which may have moved)
• Lease-up progress and tenant quality
• Rental evidence and market comparables
• Broader credit conditions and bank appetite

If any of these factors deteriorate between project commencement and completion, refinance may be unavailable on acceptable terms—or at all.

Consequences of Refinance Failure

When planned refinance doesn’t proceed:

• Construction debt remains in place at higher rates
• Extension fees and penalty rates may apply
• Lender may require forced sales
• Additional equity injection may be demanded
• Personal guarantees may be called

This risk is particularly acute for hybrid strategies where the developer plans to sell some units to pay down debt, then refinance the remainder. If sales proceeds are lower than expected, the residual debt may exceed what the retained stock can support.

Mitigating Refinance Risk

Prudent developers mitigate refinance risk by:

• Obtaining term sheets or indicative terms for refinance before committing to hold
• Building in refinance contingency (both time and cost)
• Stress-testing feasibility at higher interest rates
• Maintaining flexibility to sell if market conditions deteriorate
• Building relationships with multiple lenders before they’re needed

Ownership Structures for Long-Term Holdings

The entity structure appropriate for a development project may not be optimal for long-term property investment. This is a complex area requiring professional advice, but developers should be aware of the key considerations.

Common Structure Options

Factors to Consider

The optimal structure depends on:

• Tax treatment of rental income vs capital gains
• Ability to distribute income to different beneficiaries
• Land tax thresholds and aggregation rules
• Asset protection requirements
• Refinance and lending implications
• Exit flexibility and succession planning

The ATO’s guidance on property investment structures provides some general principles, but specific advice from qualified tax and legal advisors is essential before committing to a structure for long-term holdings.

When Each Strategy Works Best

Market conditions significantly influence which exit strategy delivers optimal returns. Understanding these conditions helps developers time their strategy decisions appropriately.

Build to Sell Typically Works Best When:

• GRV is strong and sales market is liquid
• Development margins exceed 15-20%
• Capital is needed for the next project
• Rental yields are low relative to sale prices
• Interest rates favour short-term holding
• Developer lacks investment management capability

Build to Hold Typically Works Best When:

• Rental demand significantly exceeds supply
• Cap rates are stable or compressing
• Capital appreciation is expected long-term
• Developer has investment management capacity
• Sales market is weak or uncertain
• Tax position favours rental income over capital gains

Hybrid Strategies Typically Work Best When:

• Developer wants optionality
• Some units are more attractive to hold than others
• Sales conditions are uncertain at project commencement
• Partial sales can de-risk debt position
• Developer is building a rental portfolio progressively

Momentum Wealth’s analysis of selling versus holding provides additional perspective on timing these decisions based on market cycles and individual circumstances.

Build to Rent Tax Incentives: 2024-2025 Changes

The Federal Government has introduced significant tax incentives for Build to Rent developments, passed into law in November 2024. These changes materially improve BTR feasibility for qualifying projects.

Federal Tax Changes

The Treasury Laws Amendment (Build to Rent) Bill 2024 introduced two key incentives:

The increased capital works deduction significantly improves after-tax cashflow for BTR projects. The reduced MIT (Managed Investment Trust) withholding tax rate makes Australian BTR more attractive to foreign institutional investors.

Eligibility requirements include:

• Minimum 50 dwellings available for rent
• Held under single ownership
• Minimum 10% affordable housing (for social housing provisions)
• 15-year minimum holding period for some concessions

State-by-State Land Tax Concessions

States have also introduced BTR-specific land tax relief:

The Property Council of Australia’s analysis of BTR tax settings provides comprehensive state-by-state detail. EY research commissioned by the Property Council projects these incentives could support approximately 150,000 BTR apartments by 2033.

Do These Incentives Apply to Smaller Developers?

The threshold requirements—particularly 50 dwellings minimum—mean most Federal incentives are targeted at institutional scale developments. However, state land tax concessions may have lower thresholds (WA requires only 40 dwellings), and some states are considering additional measures for smaller-scale BTR.

For boutique developers holding smaller numbers of units, the standard investment property tax treatment applies. The new BTR incentives don’t change the analysis for typical hybrid strategies involving 5-20 retained units.

Sensitivity Analysis for Hold Strategies

Before committing to a hold strategy, developers should stress-test their assumptions against plausible adverse scenarios.

Critical Variables to Test

Worked Sensitivity Example

Consider a development with 10 retained units valued at $8 million (income capitalisation at 5% cap rate), with $5 million debt:

Base Case:

• NOI: $400,000
• Interest (5%): $250,000
• DSCR: 1.60x ✓

Stress Case (rates +2%, rents -10%, cap rate +1%):

• NOI: $360,000 (reduced rents)
• Interest (7%): $350,000
• DSCR: 1.03x ✗
• Value: $6 million (6% cap rate)
• LVR: 83% ✗

This simple stress test reveals the project becomes unviable under adverse but plausible conditions. The refinance would likely fail, and the developer would be forced to sell at a loss.

Ownership Scenarios to Model Post-Completion

Developers considering hold strategies should model multiple post-completion scenarios:

Market Rentals

Standard residential letting at market rates. Model includes:

• Market rent assumptions and growth
• Standard vacancy and turnover
• Property management costs
• Standard residential lease terms

Affordable Housing

Rents set at below-market rates, potentially with government support or planning concessions:

• Discounted rent (typically 75-80% of market)
• Lower vacancy (strong demand)
• Possible subsidies or guarantees
• Longer lease terms
• Different tenant profile

Rent-to-Buy

Hybrid model where tenant has option to purchase:

• Slightly above-market rent
• Rent credits toward purchase
• Option fee income
• Exit timing uncertainty
• Complex legal documentation

Build-to-Rent (Institutional)

Purpose-built for long-term hold with professional management:

• Professional amenities and services
• Higher operating costs
• Lower vacancy targets
• Institutional exit option

Each scenario requires different assumptions and produces different risk-return profiles.

Decision Framework: Build to Sell vs Build to Hold

A structured approach helps developers make this critical decision:

Step 1: Confirm Primary Strategy Viability

If selling all units: → Standard development feasibility → Traditional funding structure → Presale-focused marketing

If holding all units: → Investment feasibility required → BTR funding structure → Rental market analysis

If hybrid (sell some, hold some): → Both feasibilities required → Complex funding structure → Proceed to Step 2

Step 2: Test Financial Viability of Hold Strategy

Can the retained units service long-term debt?

Calculate DSCR under stressed conditions:

• If DSCR > 1.3x under stress → Proceed to Step 3
• If DSCR < 1.3x under stress → Hold strategy may not be viable

Step 3: Confirm Refinance Pathway

Is refinance achievable?

• Obtain indicative terms from lenders
• Confirm valuation methodology and likely values
• Verify serviceability requirements
• Check LVR limits against projected debt levels

Step 4: Assess Tax and GST Implications

What are the tax consequences?

• Model margin scheme adjustments for retained stock
• Confirm ownership structure is appropriate
• Assess land tax implications by state
• Obtain professional advice before committing

Step 5: Document Intention and Maintain Flexibility

Whatever you decide:

• Document intention in writing at project commencement
• Include contingencies in documentation if hold is possible
• Build flexibility into funding arrangements
• Revisit decision at key milestones

Developer Checklist Before Deciding to Hold Stock

Before committing to a hold strategy, confirm you’ve addressed each of these areas:

Funding and Lending

• Refinance terms confirmed or obtained in writing
• DSCR meets lender requirements under stressed assumptions
• Rental appraisal obtained from registered valuer
• Valuation methodology understood (income capitalisation)
• Stabilisation period funding confirmed
• Interest rate sensitivity tested

Tax and GST

• Margin scheme implications modelled
• Division 129 adjustment risk assessed
• Trading stock vs capital asset treatment confirmed
• Land tax implications calculated by state
• Professional accounting/legal advice obtained

Feasibility Modelling

• Development feasibility completed (to PC)
• Investment feasibility completed (post-PC)
• Both feasibilities reconciled at completion point
• Sensitivity analysis completed on both models
• Terminal value assumptions tested

Operational Readiness

• Operating cost assumptions verified
• Capital expenditure forecast prepared
• Vacancy and incentive allowances included
• Stabilisation timeline realistic
• Property management arrangements planned

Structure and Documentation

• Entity structure appropriate for long-term hold
• Intention documented at project commencement
• Contingencies included in documentation
• Exit options preserved where possible

Conclusion: Two Different Businesses Require Two Different Approaches

Build to Sell and Build to Hold are not simply different exit strategies—they are fundamentally different financial models requiring different lending structures, different tax treatments, different valuation methodologies, and different feasibility approaches.

The transition from developer to investor represents a material shift in business model. Developers who approach hold strategies with the same mindset and tools used for sell strategies frequently encounter unexpected GST liabilities, refinance failures, inadequate returns, or operational challenges they’re not equipped to manage.

Conversely, developers who understand these distinctions—and plan for them from project inception—can build substantial investment portfolios while continuing development activities. The key is recognising that development feasibility and investment feasibility serve different purposes, and ensuring each strategy is viable on its own terms before committing.

Whether your next project is a straightforward build-to-sell, an institutional build-to-rent, or a hybrid approach, the principles in this guide provide a framework for making informed decisions and avoiding the traps that catch unprepared developers.