When should a developer involve an architect?

Before you buy. A feasibility and planning appraisal at acquisition stage protects you from overpaying for a site that cannot support the scheme you are underwriting.

What is the consentable envelope?

It is the largest scheme a site can realistically gain consent for under the relevant planning policy. Finding it is how you maximise value without tipping a scheme into refusal.

What is a Section 106 agreement?

A legal agreement between a developer and the local authority that secures planning obligations, such as affordable housing or infrastructure contributions, to make a development acceptable. It can materially affect viability and should be appraised early.

Developers

A Developer’s Guide to De-Risking Schemes at Planning

How experienced buyers protect their return by resolving planning risk before they buy and build.

Reviewed 10 June 2026 · 7 min read

A Developer’s Guide to De-Risking Schemes at Planning — illustrative image — Illustrative imagery. Not a specific AH Architecture project.

For developers, value is won or lost at planning. A scheme that maximises the consentable envelope and lands first time protects margin; one that is refused or delayed erodes it. This guide is about de-risking, not design taste.

The principle is simple: spend a little on certainty early so you are not gambling capital on hope.

Appraise the planning risk before you buy

The time to understand planning risk is before exchange, not after. A feasibility and planning appraisal tells you what the site can realistically support, where the policy constraints are, and what is likely to be resisted.

Maximise the consentable envelope

The most valuable work is finding the scheme that is both viable and consentable: the maximum the policy framework and the site can sustain without triggering refusal. That is a planning-led design exercise, not a guess.

Use pre-application advice strategically

A well-prepared pre-application enquiry surfaces the council’s position before you commit to a full submission. Used well, it shortens the route to consent and reduces the chance of a surprise refusal.

Budget for planning obligations

Larger schemes can attract planning obligations such as Section 106 agreements and the Community Infrastructure Levy. These belong in the appraisal from day one, not as a late surprise that wipes out the margin.

Frequently asked questions

When should a developer involve an architect?: Before you buy. A feasibility and planning appraisal at acquisition stage protects you from overpaying for a site that cannot support the scheme you are underwriting.
What is the consentable envelope?: It is the largest scheme a site can realistically gain consent for under the relevant planning policy. Finding it is how you maximise value without tipping a scheme into refusal.
What is a Section 106 agreement?: A legal agreement between a developer and the local authority that secures planning obligations, such as affordable housing or infrastructure contributions, to make a development acceptable. It can materially affect viability and should be appraised early.