Development Feasibility Study: What It Includes and Costs

What a property feasibility study answers

A feasibility study sits before the planning submission. Its job is to stop a bad purchase or a weak application before money is spent on either. It answers six questions.

1. What can be built? Planning policy, designations and the site's history set the limits. Design options test them.
2. What will it cost? A build cost for each option, including the site-specific extras a standard rate leaves out.
3. What will it be worth? The gross development value (GDV) of the finished homes or space, from local evidence.
4. What can you pay for the land? The residual land value, once costs and a profit are taken off.
5. How long will it take? A programme from planning to completion, which drives finance and holding costs.
6. What could go wrong? A risk register, with each risk priced or given an owner.

The answer can be no. A study that steers you away from a bad site has done its job. Consent alone does not settle the question either. Our guide on why planning permission does not mean viable shows how consented schemes still fail.

Not sure your site would pass these six questions? Send us the address, and we will tell you, free, whether a paid study is worth it.

What a development feasibility study includes

Most studies share seven parts. The depth of each depends on the site and the decision in front of you.

The build cost is the line most studies get wrong. A rate per m² is a start; a cost plan for each option is evidence. Check it allows for abnormal costs in construction, such as ground, demolition, party walls, utilities and access. In our studies, the team that would build each option prices it.

GDV and residual land value turn the scheme into a land price. National planning guidance describes GDV as "an assessment of the value of development". The line-by-line arithmetic, with a worked example, is in our guide to GDV and residual land value.

Planning obligations belong in every option. Affordable housing, section 106 and the Community Infrastructure Levy (CIL) can move land value more than any construction choice.

Who prepares a feasibility study: architect, QS or developer-builder

Several kinds of firm prepare feasibility studies. Each starts from its own trade, and that shapes the answer you get.

The gaps between these firms are where money leaks. An architect draws, a surveyor prices, a planner advises, and often nobody signs the whole answer.

A valuation is a separate job. A lender instructs its own RICS-regulated valuer for a Red Book valuation. A feasibility study is not a RICS valuation, and ours is not either.

We are a development and construction company. One firm signs each study, and our construction team prices every option. Our Development Director, Rob Barton, acquired £225M+ of land in his previous housebuilding roles.

Want one firm to sign the whole answer? Ask for a free first appraisal and we will look at your site.

Feasibility study cost and timescale ranges

Fees depend on the site, the number of options and how deep the cost and value work goes. A single figure would mislead, so we explain how fees are set.

RIBA lists three ways architects charge: a percentage of construction cost, a lump sum, or a time charge. It names the time charge, an hourly rate with capped hours, as suited to feasibility studies.

Our first site appraisal is free. A feasibility study, or a full appraisal with a lender pack, is a fixed fee per site, agreed in writing before work starts. We never charge a percentage of land value or GDV.

On timing, allow about four weeks for a full study with several options, cost plans, an appraisal and a programme. A single-option appraisal is quicker. Our free site appraisal comes back within a few working days.

A good study also puts numbers on the costs and waiting times that follow it. These are the national figures for England.

Fees come from the Planning Portal fee guide V2026.1, in force from 1 April 2026. Higher fees are proposed from 8 December 2026 in draft regulations. Decision periods come from GOV.UK and can be extended by agreement.

For a first build figure, our 2026 London rates per m² are £2,200 to £3,250 for a new-build house. A house to flats conversion runs £1,150 to £2,100, and office to residential £1,150 to £1,950. These are construction only, ex VAT and fees. Try our build cost calculator; your fixed figure comes after a survey.

Finance feasibility study: what lenders look at

A finance feasibility study usually means the study a development lender asks to see. The contents are the same as any study. The audience is stricter, so the evidence has to be.

Lenders generally focus on these points:

1. GDV evidence. Comparable sales or lettings, not asking prices.
2. Build cost. A priced cost plan with a clear scope, not a rate and a long list of exclusions.
3. Planning. The consent position, with section 106 and CIL in the numbers.
4. Programme. Realistic time for approvals, utilities and the build.
5. Contingency. Enough for the site, especially on conversions and refurbishment.
6. The team. The track record of the developer and the contractor.
7. The exit. Who will buy or rent the finished scheme, and on what evidence.

A lender instructs its own RICS-regulated valuer, and during the build a monitoring surveyor checks cost and cash flow. Our study gives that valuer a drawn scheme, a priced build cost and a programme to test.

We do not lend, arrange loans or give financial advice. This section is general information. If useful, we can introduce the lenders we work with on our own projects.

Start with the free site appraisal, before you pay for a full study or a lender pack.

Sample feasibility study structure

Writing your own, or checking one you have been sent? This structure suits most residential and mixed-use sites. Keep each section short, and show the evidence behind every figure.

1. Executive summary. The recommendation, the preferred option, GDV, build cost, land value and the main risks, on one page.
2. Site and existing use. Address, area, the current lawful use and the condition of any building.
3. Planning position. Policy, designations, history, nearby decisions and planning obligations.
4. Design options. Plans, sections and a schedule of accommodation for each option.
5. Cost plan. A cost for each option, with abnormal costs and a contingency shown separately.
6. Appraisal. GDV, costs, fees, finance, profit and the residual land value for each option.
7. Sensitivity. What happens to land value if sales fall or costs rise.
8. Programme. Dates from instruction to completion.
9. Risk register. Each risk, its likely cost and its owner.
10. Recommendation. Buy, walk away, renegotiate, or which scheme to take to planning.

On the profit line, state the figure you used and why. National planning guidance says 15% to 20% of GDV "may be considered a suitable return to developers" when councils test their local plans.

Any viability assessment sent to a council should be written on the basis that it will be made public. That is the position in national planning guidance.

Allitsen Road: a feasibility study issued in four weeks

74 Allitsen Road in St John's Wood was a vacant former private members' club, derelict inside. It was bought at auction in 2026 without proper due diligence.

We designed and priced four options, from converting the building as it stood to seven apartments. Four options, real cost plans and a GDV appraisal were issued in four weeks.

The recommended option reached 97% of the maximum GDV at 91% of the maximum cost, without excavation. Digging the basement would have added about £240k and about three months, for one one-bed worth £260k to £350k.

Raising the ground floor gave a habitable basement instead. Floor levels kept the extended building at 10.8 m, 200 mm below the 11 m sprinkler threshold. This is a feasibility study; the scheme has not been built.

Read the full Allitsen Road feasibility study. Want the same test on your own site? Get a free site appraisal.