Retail unit and shopfront structural engineering
Opening up a shopfront or converting a retail unit means removing structure at ground level and carrying everything above on a new beam. We design the openings, transfer beams and supports that make retail alterations safe, for landlords, occupiers and contractors across the UK.
Can I make my shopfront opening wider?
Usually yes, but the wider the opening the larger the beam and the more load lands on the piers at each end. We size the beam and check the supports and foundations, so we can tell you what is achievable and what the end supports need to be.
Opening up the shopfront
A new shopfront usually means taking out the ground-floor wall to create a wide glazed opening, and everything above, the upper floors, the front wall and the roof, then has to be carried on a new beam across the gap. The wider and taller the opening, the larger the beam and the more concentrated the loads at each end. We work out the load gathered above the opening, size the steel beam or, for very heavy or tall buildings, a fabricated or plated section, and design the columns and padstones that take the load down to the ground.
The end supports are the critical detail. A shopfront beam lands its whole load onto narrow piers of masonry between adjacent openings, so we check those piers for the concentrated bearing, design padstones or spreader plates to keep the stress within what the masonry can take, and design new foundations where the existing footing cannot carry the point load. Getting the bearings right is what stops cracking above the new shopfront.
Terraces, party walls and neighbours
Most retail units sit in a terrace or a parade, sharing party walls with the units either side and often with flats above. That makes the surrounding structure part of the problem. We check how the alteration affects the shared walls and the floors above, and where the work touches a party wall we coordinate with the party wall process, providing the structural information the surveyors need. Loads carried by a party wall cannot simply be removed without a route for them to travel instead.
Buildings above shops are frequently residential, so the structure has to keep the homes above safe and undisturbed. We design the beams and props so the upper floors are supported at all times, specify the temporary works needed while the old wall comes out and the new beam goes in, and keep deflection tight so finishes and flats above are not cracked by movement in the new structure.
Signage, canopies and compliance
A retail frontage carries more than glass. Fascia signage, projecting signs, canopies, awnings and security shutters all hang off the structure and apply their own loads, including wind load on anything that projects into the street. We design the supports and fixings for these elements to BS EN 1991-1-4 for wind, so a projecting sign or canopy is properly held and does not work loose or pull the fixings out of the wall.
The design is prepared to the Eurocodes, the relevant UK National Annex and Approved Document A, and issued as calculations and drawings the contractor can build from and Building Control can approve. Where the unit is being converted between uses, for example a shop to a cafe or a restaurant, we address the change in floor loading and any new plant as part of the same structural package.
What we check.
The points our calculations resolve for a project like this.
- Transfer beam sizing to carry upper floors, front wall and roof
- Concentrated bearing on narrow masonry piers between openings
- Padstones, spreader plates and new foundations at the beam ends
- Party walls and floors above coordinated with the party wall process
- Temporary works to support flats and upper floors during the works
- Signage, canopy and shutter fixings designed for wind load
From enquiry to sign-off.
Enquiry
Send drawings or describe the problem. We confirm the scope, the deliverables and a target timescale.
Information
We agree the survey, drawings or data we need and any site access required.
Engineering
Design, calculation or assessment to the relevant Eurocodes and UK National Annex.
Issue
A clear, defensible report or set of calculations, with assumptions and limitations stated.
Common questions
Can I make my shopfront opening wider?
Usually yes, but the wider the opening the larger the beam and the more load lands on the piers at each end. We size the beam and check the supports and foundations, so we can tell you what is achievable and what the end supports need to be.
There are flats above the shop. Is that a problem?
It is manageable with the right design. We keep the upper floors supported at all times, design the temporary works for while the old wall is removed, and keep deflection tight so the flats above are not disturbed or cracked.
Do you deal with the party wall side?
We provide the structural information the party wall surveyors need and design the works so loads carried by a shared wall have a safe new route. The party wall notices themselves are handled by a party wall surveyor, and we coordinate with them.
Can you design signage and canopy fixings?
Yes. Fascia signs, projecting signs, canopies and shutters apply load, including wind load on anything that projects, and we design the supports and fixings for them. We work with retail clients across the UK.
Related in commercial, industrial & agricultural structural engineering.
Tell us what you are building.
Send the drawings or describe the project. We confirm scope, deliverables and a realistic timescale.
Start a project