The question of whether an architect is worth the cost for a smaller project is one we respect. Not every project needs the same level of professional input, and a good architect will tell you honestly when their full service isn't warranted.

But 'small' is a relative term — and the answer depends less on the physical size of the extension than on what the project is trying to achieve and what is at stake if it goes wrong.

Planning sensitivity is the first consideration. If your property is in a conservation area, is a registered building, or sits in a location where planning permission is not straightforward, the planning expertise an architect brings is disproportionately valuable relative to their fee. A refusal costs time and money — and sometimes results in a project being abandoned entirely.

Design quality is the second. An extension that creates a genuinely better home — that brings light into a dark space, opens up a relationship with the garden, or solves a spatial problem that has frustrated the family for years — is worth more than one that simply adds square footage. Getting that quality of result from a smaller project requires the same quality of thinking as a larger one.

Complexity is the third. A single-storey rear extension to a simple detached house with no planning constraints, a straightforward structural situation, and a standard specification is a relatively simple project. The same footprint extension to a semi-detached property with party wall implications, unusual site levels, and a sensitive planning context is a much more complex one — regardless of its size.

On a project with a construction cost of, say, £80,000 to £120,000, architectural fees for a full service — from design through planning through construction drawings and site oversight — might be in the region of £10,000 to £18,000. That represents roughly 10% to 15% of the construction cost.

For that investment you get a design that has been properly thought through, a planning application that has been professionally prepared, construction drawings that give builders accurate information to price and build from, and a professional on your side throughout construction whose job is to look after your interests.

The alternative — saving those fees and managing the project yourself, or using a less qualified person to produce the drawings — is not without risk. Errors in drawings, planning refusals, construction problems, and disputes with contractors all have costs. The question is whether those risks are likely to be more or less than the fee you are trying to avoid.

For projects with a construction cost above roughly £60,000 on the Isle of Man, we believe the value of a full architectural service is almost always justified. Below that threshold, a partial service — design and planning only, for example — may be the right approach. And for very small projects with no planning complications and simple construction, we would tell you that directly rather than take on work that doesn't need us.

The right answer depends on your specific project. The best way to find out is to have a conversation with us.