Case Study: Converting a House into 3 Flats — Hook Road, Surbiton
How we converted a Surbiton house into three flats in 6 months: planning permission with no objections from a difficult council, a £350,000 build managed weekly, and what the client said about it.
Project: conversion of a house into 3 self-contained flats Location: Hook Road, Surbiton Service: Project Management (Gold package — 10% of build cost, £35,000) Build period: 6 months Build cost: £350,000 plus VAT at 5%
The client's starting point
The client came to us on a recommendation and spoke to four companies before choosing. Their concerns going in, in their own words:
- Gaining planning permission from a council renowned for being "difficult"
- A clear return on investment with a pre-defined budget
- Seamless pricing structures
- Quality of design with specific regard to space
- Appointment of a good quality, skilled building contractor
- Ongoing project management and clear lines of communication
Converting a house into flats is a material change of use — full planning permission territory, with unit sizes, amenity and parking all scrutinised. On a development project the planning strategy isn't paperwork; it's the difference between a viable scheme and an expensive refusal.
What happened
Planning: approved with no objections. The design was built around what the council could approve, not negotiated after a refusal — the same approach we described in our Tandridge planning guide.
Tendering: twice back to the drawing board. The first round of builder quotes came in over budget. Rather than letting the budget slide, we revised and re-tendered until price and specification lined up. In the client's words: "Ashton and his team went back to the drawing board twice during this selection process and I could not be happier with the final choice."
Build: managed weekly, paid on completion only. "My PM from Ashton Paul is on site every week without fail, reporting any issues and keeping a watchful eye on the progress to ensure that I pay only for work completed to date and that the builders continue to adhere to timescales laid down in the contracts."
Six months after starting on site: three finished flats.
Why it worked
Every risk on this project — difficult council, over-budget tenders, contractor quality — was managed by process, not luck: design-led planning, competitive tendering against a fixed specification, and weekly independent inspection tied to stage payments. It's the same discipline we apply to home extensions and covered in who to call first when planning building work.
"As far as recommending Ashton Paul as your go-to partner for this type of project, I would wholeheartedly encourage you to do so."
Thinking about a conversion or development?
Whether it's a house-to-flats conversion, an extension or a full renovation, the process starts with a feasibility conversation — book a free consultation and we'll tell you honestly whether your project stacks up.