Structural design for new homes, flats and mixed-use buildings up to 15 m
Full structural design for new apartment blocks, terraces and mixed-use buildings up to 15 metres and five storeys, in steel, concrete, masonry or timber frame.
About this service
A new building is designed from the ground up, which gives the structural engineer the most influence over cost and buildability. Choices about the frame, the column grid and the foundations made at the start shape everything that follows, from floor-to-floor heights to how quickly the contractor can build. We provide full structural design for new blocks of flats, terraces and mixed-use buildings up to 15 metres high and five storeys, working with your architect from early layouts to construction issue.
Our clients here are small and medium developers, self-builders on larger plots, and architects who want an engineer they can work with closely. Typical schemes include infill blocks on corner sites, flats over ground floor shops, mews and backland terraces, and replacement buildings on cleared sites. Mixed-use schemes often need a transfer structure where flats sit over an open shop floor, and our transfer structure and podium design can be included.
London adds its own challenges. Tight sites with neighbours on several sides, London Clay that shrinks and swells near trees, sewers crossing the plot and strict construction management requirements all shape the structural design. Every set of calculations and drawings we issue passes through our three-step quality control process, with final sign-off by our Head of Engineering, before it goes to Building Control.
When you need it
- You are developing a new block of flats or a building with commercial space below homes
- Your scheme is up to 15 metres high and up to five storeys
- You need a structural engineer from planning through to construction
What's included
- Structural scheme and frame selection with the architect
- Foundation, frame, floor, roof and stability design
- Robustness and disproportionate collapse design to Building Regulations Part A
- Calculations and drawings for Building Control and tender
- Coordination with the architect, M&E and fire engineers
How it works
- Concept and frame optionsWe review the early layouts, site constraints and any ground information, then compare frames such as masonry, timber, steel or reinforced concrete for cost, weight, programme and floor depth.
- Ground and foundationsWe specify or review the ground investigation, assess tree influence and existing sewers, and select a foundation type such as strip footings, a raft or piles to suit the soil and loads.
- Scheme designWe set the structural grid, size the main members, develop the stability system and design for robustness to Building Regulations Part A, coordinating with the architect, M&E and fire engineers.
- Detailed designWe complete the calculations and produce general arrangement and detail drawings for foundations, floors, frame, roof and connections, ready for Building Control approval and tender.
- Construction supportWe answer contractor queries, review temporary works interfaces and fabrication drawings where agreed, and issue revisions so the construction-issue set stays current.
What you receive
Choosing the right frame for a low-rise London scheme
There is no single best frame. Loadbearing masonry is economical for repetitive flat layouts with walls that stack. Timber frame and cross-laminated timber are light, quick to erect and lower in embodied carbon, which also helps on weak ground. Steel suits open commercial floors and long spans, and reinforced concrete flat slabs give thin floors and flexible layouts. We compare these with your architect and cost consultant before planning drawings fix the floor-to-floor heights.
Foundations deserve early attention. On London Clay, removing trees or building near retained ones can cause heave or shrinkage, so foundations may need to go deeper or be piled, with heave protection under slabs and ground beams. Our guide to London Clay, trees and foundations explains the principles. A sewer crossing the site may need diverting or a build-over approval, which can move the footprint.
The most common mistake is bringing the engineer in after planning. By then the grid, storey heights and any basement depth may be fixed in ways that make the structure more expensive. Even a short early appointment lets us flag transfer beams, column positions and stability walls while they are still easy to move. Our new-build design covers buildings up to 15 metres and five storeys, and we do not take on taller schemes.
Not included
- Buildings taller than 15 metres or more than five storeys
- Specialist façade and cladding design
Frequently asked questions
When should I appoint a structural engineer for a new build?
Ideally before the planning drawings are finalised. Early input helps fix a sensible structural grid, realistic floor depths and the right foundation type, all of which affect planning heights and cost. Some councils also ask for structural or basement information with the application. Appointing late often means reworking layouts to fit beams and columns that were never allowed for.
What is disproportionate collapse?
It is the risk that local damage, such as the loss of a wall or column, causes a much larger part of the building to collapse. Building Regulations Part A requires buildings to be designed against it, with the measures depending on the building's use and number of storeys. For flats, requirements such as horizontal and vertical ties or key element design become more demanding as the storey count rises.
Is timber frame or masonry cheaper for a block of flats?
It depends on the site, the layout and the contractor. Masonry is often economical for simple, repetitive layouts. Timber frame is quicker on site and lighter, which can reduce foundation costs on weak ground. Steel or concrete may suit mixed-use buildings with open ground floors better. We give you a clear structural comparison so your cost consultant or contractor can price the options properly.
Will I need piled foundations on London Clay?
Not necessarily. Many low-rise buildings on London Clay sit on deep strip or trench fill foundations, or on a raft. Piles become more likely with heavier buildings, nearby trees, made ground, tight boundaries or where trench fill would need to be very deep. A ground investigation and tree survey let us choose properly, and our ground investigation service can provide the site data.
How much does structural design for a new block of flats cost?
Our structural design for new residential and mixed-use buildings starts from £3,500 + VAT. The fee depends on the size and complexity of the scheme, the frame type and the level of construction support you need. We confirm a fixed fee in writing before any work starts, with a typical turnaround of 10 working days confirmed alongside it.