Ballpark figure for a London bungalow?

[BeckyG]

Hi, I know it is impossible to say with any certainty, but I am at the stage of having a plot (my garden, so I already owned it) and a basic design (drawn by a relative who is a retired architect) and have been to pre-planning advice. The planning dept raised no objections to the plan, but have asked for a number of surveys (tree impact assessment, method statement, noise survey, land contamination survey ...) as well as technical drawings showing various things so to progress further I will now have to commit quite a bit of money. I will also need to find an architect to take the design to the next stage (building reg drawings and tender drawings). So we are talking £££ but so far I have no idea how much the build will cost beyond the m/sq estimates online, and I would love to hear any thoughts people have on this forum.

 

The design is for a single storey house with 2 bedrooms and one bathroom, 100 m/sq. It would have a living roof (needed for planning, and I like them) and has been designed with floor-ceiling windows in the main living area (this could change if prohibitively expensive). Materials - part brick, part timber clad. I don't know about construction methods (no technical drawings yet).

 

My budget is £300k - this is finite because I have retired, so I can't get a mortgage - my plan is to use my savings and release equity from my house (which I would then sell once the new house is ready to move into). I haThe only wriggle room we have on budget is that we could move into the house before all the finishing was done - so long as it was habitable, we could do the flooring etc later, once we have released money from the sale of the existing house. In terms of fees, I need to find an architect who is willing to just do the technical and tender drawings working from an existing design - I don't know how easy that will be or what they would charge. I don't feel capable of project managing so would be looking for a contractor or design and build company to take the project forward once planning permission has been granted. 

 

All thoughts welcome!

[Hasteron]

On 03/06/2025 at 17:49, BeckyG said:

Hi, I know it is impossible to say with any certainty, but I am at the stage of having a plot (my garden, so I already owned it) and a basic design (drawn by a relative who is a retired architect) and have been to pre-planning advice. The planning dept raised no objections to the plan, but have asked for a number of surveys (tree impact assessment, method statement, noise survey, land contamination survey ...) as well as technical drawings showing various things so to progress further I will now have to commit quite a bit of money. I will also need to find an architect to take the design to the next stage (building reg drawings and tender drawings). So we are talking £££ but so far I have no idea how much the build will cost beyond the m/sq estimates online, and I would love to hear any thoughts people have on this forum.

 

The design is for a single storey house with 2 bedrooms and one bathroom, 100 m/sq. It would have a living roof (needed for planning, and I like them) and has been designed with floor-ceiling windows in the main living area (this could change if prohibitively expensive). Materials - part brick, part timber clad. I don't know about construction methods (no technical drawings yet).

 

My budget is £300k - this is finite because I have retired, so I can't get a mortgage - my plan is to use my savings and release equity from my house (which I would then sell once the new house is ready to move into). I haThe only wriggle room we have on budget is that we could move into the house before all the finishing was done - so long as it was habitable, we could do the flooring etc later, once we have released money from the sale of the existing house. In terms of fees, I need to find an architect who is willing to just do the technical and tender drawings working from an existing design - I don't know how easy that will be or what they would charge. I don't feel capable of project managing so would be looking for a contractor or design and build company to take the project forward once planning permission has been granted. It’s a bit like navigating any specialized field where expert help makes all the difference — I’ve seen people face the same thing when looking into things like live video streaming app development where the concept is clear, but the execution needs real technical support.

 

All thoughts welcome!

You're in a very similar position to where I was a couple of years ago — plot already owned, initial design by a relative, and planning advice with a long list of surveys. It does feel like a leap of faith when you’re committing real money before having a firm grasp on build costs. That said, your budget of £300k for 100 m² sounds achievable, especially if you’re flexible on finishes and open to moving in before it’s 100% done. The living roof and floor-to-ceiling glazing could eat a chunk of the budget though, depending on spec. I found it totally possible to get an architect just for technical drawings, but some were pickier than others — it helped to ask smaller, local firms. Also, having a main contractor manage things was a life-saver for me since I didn’t want to be hands-on. Good luck — sounds like a lovely project!