Avoid these Construction Loan Mistakes for Extensions

Extension projects in Eltham often involve working with existing character homes on substantial blocks, where the finance structure needs to accommodate both the property you already own and the build you're planning.

Construction finance for an extension differs from a standard home loan because funds are released progressively as the work advances, rather than in a single settlement. The lender charges interest only on the amount drawn down at each stage, which means your repayments start lower and increase as more funds are released. Most lenders structure these as interest-only repayment options during the construction phase, converting to principal and interest once the extension is complete and valued.

Council Approval and DA Requirements for Eltham Extensions

Your lender will require council approval before releasing any funds. In Eltham, many homes sit within heritage overlays or significant landscape areas, which means your development application may face additional scrutiny from Nillumbik Shire Council. The approval process can take longer than in other municipalities, particularly if your extension affects existing vegetation or alters the roofline of a period home.

Consider a property owner extending a 1970s home near the Diamond Creek escarpment. The council required amended plans to address bushfire management overlays and tree protection zones, delaying approval by six weeks. Because their construction loan required the builder to commence building within a set period from the Disclosure Date, they needed to renegotiate the start date with both the builder and the lender to avoid the loan offer expiring.

Most lenders allow 12 months from loan approval to the first drawdown, but if council approval drags beyond that window, you may need to reapply. That means fresh valuations, updated financials, and potentially different interest rates if market conditions have shifted.

Fixed Price Building Contracts and Variation Management

Lenders prefer fixed price contracts because they provide certainty around the loan amount. A cost plus contract, where you pay for materials and labour as invoiced, creates uncertainty for both you and the lender about the final cost. Most mainstream banks won't approve construction funding under a cost plus arrangement unless you're an owner builder with significant equity.

Even with a fixed price building contract, variations can push your costs beyond the approved loan amount. If your builder discovers asbestos during demolition or the soil test reveals the need for additional footings, those costs sit outside the original contract. You'll need to cover variations from your own funds unless you've built a buffer into your borrowing or can access additional funds through refinancing your existing mortgage.

How the Progressive Drawdown Process Works

The construction draw schedule typically includes four to six stages: base stage (slab or footings), frame stage, lock-up stage, fixing stage, and practical completion. Each stage requires a progress inspection by the lender's valuer, who confirms the work matches the progress payment schedule before releasing funds.

The inspection process adds time between when your builder requests payment and when they receive it. In our experience, inspections in areas like Eltham can take longer to arrange than in metro suburbs, particularly during peak building periods. Your builder may request a deposit upfront to cover initial costs, typically around 10% of the contract value, which you'll need in accessible funds before the first drawdown.

Lenders also charge a Progressive Drawing Fee for each inspection and drawdown, usually between $250 and $400 per stage. Over a five-stage build, that adds $1,250 to $2,000 to your total borrowing costs. Some lenders cap this fee or waive it for larger loan amounts, but it's worth factoring into your budget.

Matching Your Loan Amount to Actual Build Costs

The loan amount needs to cover both the construction contract and associated costs such as permits, engineers' reports, asbestos removal, temporary fencing, and connections for plumbers and electricians. These ancillary costs often add 15% to 20% on top of the builder's quoted price, particularly for extensions where services need to be relocated or upgraded.

A common issue arises when the valuation comes in below the builder's quote plus costs. If the valuer assesses the completed extension as adding less value than the build costs, the lender may reduce the approved loan amount. This happens more often with highly specific or personal design choices that don't align with broader market expectations for the area.

For example, if you're building a two-storey extension on a single-level home in Research or Lower Plenty, where the market strongly favours single-level living, the valuer may assess the completed value conservatively. You'd then need to cover the shortfall yourself or scale back the project.

Construction Loan Interest Rates and Conversion Terms

Construction loan interest rates during the build phase are typically variable, even if you plan to fix the rate once construction completes. The lender calculates interest daily on the drawn balance, which means your repayments increase each time a progress payment is released.

Once the build reaches practical completion and the final valuation is done, the loan converts to a standard home loan. At that point, you can choose to fix all or part of the rate, switch to principal and interest repayments, or explore refinancing to reduce your rate if other lenders are offering better terms. Locking in your post-construction loan structure too early can limit your options if rates have moved significantly during the build.

Using Equity from Your Existing Property

Most extension projects are funded by accessing equity in the property being extended. The lender values the property in its current state, then applies a loan-to-value ratio (typically 80% to avoid lender's mortgage insurance) to determine how much you can borrow against it. That borrowing capacity needs to cover both the land value and the construction costs.

If you purchased your Eltham property several years ago, you may have substantial equity available. However, if you bought recently or have an existing mortgage with a high balance, your usable equity may be limited. In that case, you might need to bring additional savings, consider bridging loans if you're selling another property, or stage the extension across multiple builds as equity grows.

Timing the Build with a Registered Builder

Your builder must be registered and insured for the lender to approve the loan. In Victoria, that means current registration with the Victorian Building Authority and appropriate domestic building insurance. The lender will request copies of these documents as part of the construction loan application, and they must remain valid for the duration of the build.

If your builder's registration lapses or their insurance is cancelled mid-project, the lender can freeze further drawdowns until the issue is resolved. That leaves you liable for progress payments to sub-contractors while the builder sorts out their compliance, which creates significant financial pressure.

If you're considering an extension to your Eltham property and need clarity around how construction loans are structured for this type of project, we can walk through your specific situation and builder arrangements. Call one of our team or book an appointment at a time that works for you.

Frequently Asked Questions