design development & cost consultancy

balancing vision with value

Successful projects strike the right balance between design ambition and financial reality. At Congreve Horner, our design development and cost consultancy services ensure your project is both creatively inspired and commercially viable — from concept through to completion.

early insight. smarter decisions.

We support clients during the crucial early stages of a project, offering technical guidance, feasibility insight and cost advice. By shaping design decisions with a clear understanding of budget, buildability and compliance, we help you avoid costly redesigns and keep your project firmly on track.

Feasibility with Focus

We assess site constraints, planning considerations, and client objectives to define what’s achievable — and what’s not. Our early involvement helps clarify options and reduces the risk of delays or unforeseen costs, later down the line.

Value-Led Design Development

Working alongside architects and design teams, we ensure that proposals remain practical, compliant and aligned with your budget. We help refine specifications, assess materials and advise on build methods — so you get the best value without compromising quality.

Accurate Cost Planning

With robust cost estimates and financial forecasting at every stage, you stay in control of your budget. We provide cost plans, tender evaluations and lifecycle cost advice, giving you the confidence to commit, invest and proceed with clarity.

Andrew Dewhurst is the most thorough, professional and hard-working surveyor you will ever find.

Both very detailed and very clear and easy to understand. Could not recommend more highly, either for a standard survey, or for very complex issues. Exceptional.

Simon Parry, Google Review

Everyone at Congreve Horner was really nice and professional to deal with.

I mostly dealt with James, a really nice reasonable person who helped me get what I wanted from the extension. I am so glad he led me to a better redesign and extension. From beginning to end the project management was exceptional.
Siobhan Costello, Trustpilot

We appointed John as the Project Manager and Employers Agent for the extension and refurbishment works at our Listed Knightsbridge flat.

He had come highly recommended, by a close friend. John managed a large team of designers, contractors and specialists in addition to working with the Grosvenor Estate, in order to make sure that the works were completed on time and on budget. This also included dealing with complicated insurance and contractual claims, as a result of a fire, in another part of the building, which caused significant damage, during the works. Without Johns expertise and cool head, I am sure we would not have been able to deal with the works or certainly the subsequent claims process in such a proactive and decisive manner. I felt reassured to have John involved, throughout.

Mateo Kovačić, Manchester City and Croatian National team football player

John and I have been working together for over 10 years now and he personally has managed all of our developments, ranging from small new build 9-unit developments to larger 120-unit new build developments.

These contracts range from £2m to £30m. John has a keen eye for details and manages the team well, which varies depending on complexity of the projects. John regularly takes on the role of financial advisor, employers agent and project manager, on the smaller projects and is our Projects Director, managing larger teams of consultants, on the larger projects.

I have found John to be crucial in ensuring the smooth running of the project whilst keeping a firm grip on the financial aspects of the build and knowing how to deal with problems, whether they be contractual, financial or construction detailing.

William McKenna, Director, Luxgrove Capital Partners

John Hession of Congreve Horner has acted for us both personally and for Miles and Miles Property Ltd on a number of developments in London and the Home Counties.

John played a key role in cost planning, tender preparation, and project cost control. He worked collaboratively with different contractors and project teams and consistently demonstrated a high level of technical competence and attention to detail. John ensured budgets and timescales were met and was instrumental in the successful completion of our developments.

Simon Grime, Director, Miles and Miles Property Limited

I brought John on as a project manager after a trusted friend recommended him, having used him for a complex build of their own. From day one, John proved to be an invaluable asset.

He brought a level of expertise and professionalism that gave me real peace of mind, especially when dealing with contractors on a demanding basement extension. He kept a close eye on the budget and was always available to explain things clearly, cutting through the jargon and helping me make informed decisions. I wouldn’t hesitate to recommend him to anyone taking on a major project.

Anton Morozov, Director, GMG Brokers Limited