A feasibility study with two or three drawn options, £449 fixed
Rear extension or side return? Loft or both? Before you pay for a full set of drawings, see what each option looks like, what it adds and which planning route it needs. We draw them side by side: £449.
- £449 fixed, no survey fee
- Two or three options drawn
- Planning route shown for each
What does a feasibility study cost?
The fee is £449, with no survey fee and no VAT to add. For that we draw two or three different ways to do what you want, compare them on space, cost drivers and planning route, and recommend one. You then choose, and the chosen option becomes the brief for the full drawings.
This report is written up in full on our sister site propertyarchitecture.com. Our fixed fee below still applies if you order through us. Read it on propertyarchitecture.com.
What the £449 covers
- A conversation about what you want, how you live and what you are willing to spend
- Two or three options, each drawn as a plan with the new space marked and a simple massing sketch
- A comparison table: floor area gained, planning route, main cost drivers and the main risk of each
- The planning route for each option: no application, prior approval or planning permission
- A written recommendation, so the choice is yours but the reasons are clear
What an option study shows that a quote does not
That the same wish can be built three ways, and each lands differently on space, route and risk. A 6 m rear extension can go through prior approval for £249 in council fees, where a scheme deeper than that needs a £548 application (fees). Which one is right depends on how much room you need and how much risk you will take on the neighbours.
Government guidance says early engagement improves the quality of an application and its likelihood of success (gov.uk). The study is our version of that, done for you before any council is involved.
What counts as an option
A genuinely different answer, not a tweak. For a family wanting one more bedroom and a bigger kitchen, the options might be a side-return extension, a rear extension to the permitted limit and a loft conversion with a smaller kitchen change. Each is drawn at the same scale, so you compare like with like.
- Same site, same brief, different approach
- Area gained, shown on a plan
- The planning route and what could stop it
- The main thing that would make it dearer on site
From option to full drawings
Once you choose, the option becomes a brief for planning drawings, or a Lawful Development Certificate if it is permitted development. If the full job needs a measured survey, it is charged once. The study does not promise a decision from the council, and pre-application advice cannot either (gov.uk).
Why test options before you draw in detail
- Pre-application
- Government guidance says pre-application engagement can improve the quality of applications and their likelihood of success, and cut delays at validation. gov.uk, Before submitting an application
- Not binding
- Pre-application advice cannot pre-empt the council’s decision or a particular outcome, although it can be a material consideration. gov.uk, Before submitting an application
- 3 m / 6 m
- A single-storey rear extension may go 3 m from the original rear wall of an attached house without notice, or 6 m through prior approval, so the choice of depth chooses the route. MHCLG permitted development technical guidance, Class A, p.17
- 50%
- Everything built around the original house together must not cover more than half of the surrounding land. MHCLG permitted development technical guidance, Class A, p.10
- 8 weeks
- A council has 8 weeks to decide most planning applications, so an option that needs one is slower than one that does not. gov.uk, Determining a planning application
- £548
- A householder planning application costs £548 from 1 April 2026, against £249 for a larger home extension prior approval. National fee schedule from 1 April 2026, published by Bradford Council
Feasibility study questions
How many options do I get?
Two or three, depending on the brief. Each is drawn at the same scale and compared on the same points.
Does the study tell me if the council will approve?
No. It tells you the route and the risks. Even pre-application advice from a council cannot pre-empt a decision.
Is the £449 taken off the full drawings?
No. It is a separate fixed fee. The study saves you from paying for full drawings of the wrong option.
Do I pay for a survey on top?
Not for the study. If you go on to full drawings that need a measured survey, it is charged once, at £150.
Can I ask the council for pre-application advice as well?
Yes. Councils may charge for it, and the charge must not exceed their cost. The study gives you something concrete to take to them.
Other services people book with this one
Not sure which way to build?
Send the address and what you want from the house. We reply with a fixed fee for two or three options.