Structural engineering fees can feel like a bit of a mystery — the costs aren't always advertised clearly, and it can be hard to know what's reasonable. Here's an honest breakdown of what structural engineers typically charge in South East London, and what drives the cost.
Structural inspection and report — £400 to £800
If you need a structural engineer to inspect a residential property and produce a written report — perhaps because a survey has flagged significant cracking, or you're buying a property with known structural concerns — expect to pay between £400 and £800 for most standard properties.
The cost varies based on the size of the property, the complexity of the structural issues, and the scope of investigation required. A simple crack assessment on a two-bedroom flat costs less than a full structural inspection of a large Victorian detached house with multiple concerns.
Extension structural calculations — £400 to £1,000+
For a typical single-storey rear extension, structural calculations (required for Building Regulations) generally cost between £400 and £800. For a double-storey extension, a loft conversion, or a basement, expect to pay more — often £800 to £1,500 or beyond for complex projects.
The fee covers the engineer's site visit, calculations, structural drawings, and any liaising with Building Control. Read more about structural engineers for extensions here.
RSJ and beam calculations — £300 to £600
If you're removing a load-bearing wall and need calculations for the replacement steel beam (RSJ), this is a more focused piece of work. Expect to pay between £300 and £600 for a straightforward residential beam calculation — including the padstone and bearing specifications required by Building Control.
Party wall structural assessment — £300 to £600
When works near a shared boundary could affect a neighbouring property's structure, a structural assessment may be required as part of the Party Wall process. Costs are similar to beam calculations for most standard cases.
💡 Always ask for a fixed fee upfront, not an hourly rate. Fixed fees protect you from bill creep and make budgeting straightforward. At SurveyCORE we quote fixed fees on all structural engineering work.
What affects the cost?
The main factors that influence structural engineering fees are:
- Scope of work — a crack assessment is simpler than full extension calculations
- Property size and complexity — larger or more complex structures take longer to assess
- Number of site visits required — some projects need follow-up visits
- Drawing requirements — detailed structural drawings add to the fee
- Location — South East London rates reflect the higher cost of operating in the capital
Is structural engineering worth the cost?
In the context of a property purchase worth hundreds of thousands of pounds, or building works costing tens of thousands — yes, almost always. Structural engineering fees are a small fraction of the overall project cost, and the consequences of getting the structural work wrong are severe.
Beyond cost, there's the legal dimension: Building Control requires certified structural calculations for most structural work. Without them, you can't get sign-off — and without sign-off, you'll have serious problems when you come to sell.
📋 Need a structural engineer in South East London? Get a fixed-fee quote from SurveyCORE — covering Bromley, Beckenham, Sidcup, Lewisham, Dulwich, Bermondsey and across the South East.