Structural Engineers in Leeds

The Leeds housing stock, era by era

Leeds contains every structural era we deal with, often within a few streets of each other, and each one brings its own predictable set of defects. Knowing which era a building belongs to tells an engineer most of what to expect before they open the door.

None of these are reasons to avoid a house. They are the things worth looking at properly on the house you are actually buying or altering.

• Pre-1850 stone cottages and farmhouses, in the outer villages and up towards Otley and Bramhope - solid stone walls, shallow or no formal foundations, heavy stone slate roofs, and thick walls that often turn out to be rubble-filled rather than solid. Bulging, roof spread and failed stone lintels are the recurring questions.
• Victorian and Edwardian back-to-backs and through terraces, in Harehills, Armley, Beeston, Holbeck, Burley and Hyde Park - Leeds holds the country's largest surviving stock of back-to-backs and went on building them later than anywhere else. Shallow foundations, lime mortar, cellars, party walls shared with two neighbours rather than one, gable bowing on end terraces, and chimney breasts removed by somebody at some point without support.
• Interwar semis and estates, across Moortown, Halton, Gipton, Meanwood and Cross Gates - cavity walls with wall ties now approaching or past the end of their design life, concrete lintels, and the era where wall tie corrosion produces its characteristic regular horizontal cracking.
• Post-war and system-built housing, including non-traditional and concrete construction - where the structural question is often about mortgageability and the condition of the frame rather than about cracking at all.
• 1960s to 1990s estate housing - trussed rafter roofs that must not be cut about for a loft conversion, shallow strip foundations, and floors that bounce because the joists were sized to the limit.
• City-centre mill and warehouse conversions, and modern apartment stock - cast iron columns, jack arch floors, heavy timber, and thick masonry walls that were designed for a use nobody has now.

The ground under Leeds

Leeds sits across a genuine geological boundary, and it changes what an engineer is looking for from one side of the city to the other.

Broadly, the Coal Measures run beneath the south and west of the district - which brings the coalfield questions with them: historic shallow workings, shafts, and made ground from spoil and infill. Towards the north and west the ground rises onto the Millstone Grit, which is why the outer villages are built of the stone they stand on. Through the middle runs the Aire valley, with its alluvium and river terrace deposits - softer, more variable, wetter ground than the higher land either side of it.

Two more local factors turn up repeatedly. The first is glacial clay in parts of the north of the city, where mature trees and a dry summer can produce genuine shrinkage movement - the classic South East England mechanism, occurring here in patches rather than everywhere. The second is water in the wrong place: Leeds culverted a great many of its becks in the nineteenth century, and a defective culvert or a leaking drain washing fines out from beneath a foundation is a much more common cause of localised subsidence here than most homeowners expect. It is also, encouragingly, one of the cheaper causes to put right once it has been identified.

The practical consequence is that cracking in south Leeds and cracking in north Leeds get investigated differently. Neither is investigated by looking at a photograph.

Leeds City Council Building Control, and how long approval takes

Most structural alterations to a house are notifiable work under the Building Regulations - removing a load-bearing wall, taking out a chimney breast, forming a large opening, converting a loft, building an extension. Notifiable means Building Control has to know about it before it happens, and has to sign it off afterwards.

There are two routes. Leeds City Council's own Building Control service is the local authority route; the alternative is a registered private building control approver. Either way the structural side of the submission is the same: calculations and details showing what is carrying the load, from a competent engineer.

On timescales, the part that is fixed in law is the determination period for a full plans application - the authority must decide it within five weeks, or within eight weeks if you agree to an extension in writing. In practice, for straightforward domestic structural work, the thing that governs the programme is not the authority at all: it is how quickly the calculations arrive and whether they answer the questions first time. A submission that triggers a query has to go round again.

The smaller route is a building notice, used for simpler work, where there is no plan check in advance and the inspector assesses the work on site. It is quicker to start and it carries a risk: if the inspector is not satisfied with what has been built, it is being changed after it exists rather than before. For anything involving a beam, we would rather the calculations existed first.

One last point, and it is the one that costs people money years later. Get the completion certificate. It is the document a buyer's solicitor asks for, and unevidenced structural work is one of the most common reasons a Leeds sale stalls at the enquiries stage.

What we are asked for most often in Leeds

In rough order of volume, across an ordinary month:

• Steel beam calculations and Building Control packages for removing a load-bearing wall - the single most common instruction we take
• Chimney breast removals, and inspections of chimney breasts somebody else removed without support
• Loft conversion structural design, including the roofs that cannot simply be cut about
• Extension foundation and superstructure design, and the drainage that goes with it
• Structural surveys and reports on cracking, movement, sloping floors and bouncing floors
• Pre-purchase inspections where a valuation or a homebuyer survey has been referred to an engineer
• Retaining wall assessment and design, which the city's sloping sites generate more of than people expect
• Commercial structural appraisals, mezzanine design and alteration work in the older commercial stock

What it costs, and how long it takes

A structural survey and report in Leeds is a fixed £580 + VAT. That is the published fee and it does not move once the property and the scope are confirmed - no hourly rate running in the background, and no separate charge for producing the report.

The report is with you within 10 working days of the inspection, guaranteed. We treat the date as a commitment rather than an estimate, which matters if you are working to an exchange date. If you have a deadline, say so when you enquire and we will tell you before you commit whether we can meet it.

Design work - beam calculations, a chimney breast support, a foundation design, a Building Control package - is a different and usually smaller piece of work, quoted individually against what you actually need. Tell us the job and you get a fixed figure in writing before anything starts.

Recent Leeds work

Two of the projects in our portfolio are Leeds jobs and they sit at opposite ends of the range: a domestic house extension, and a light industrial unit with a mezzanine. Both are set out with the requirement, the engineering challenge, what we designed and how it came out - the case studies are linked below.

The wider picture is less photogenic and more representative: a steady flow of beam designs for local builders, surveys on terraced and semi-detached houses across the city, and reports written to unstick a purchase that a valuer has referred.

Where in Leeds we work

Everywhere in the metropolitan district. Inner Leeds - Armley, Beeston, Harehills, Headingley, Holbeck, Hyde Park, Burley, Chapel Allerton, Meanwood, Roundhay and Moortown - is where most of the survey work is, because that is where the older housing is. Horsforth, Guiseley, Yeadon, Otley, Bramhope and Adel to the north and west; Pudsey, Farsley and Calverley to the west; Morley, Rothwell, Middleton and Belle Isle to the south; Cross Gates, Garforth, Whinmoor and Seacroft to the east; Wetherby and the villages beyond.

We have not built a separate page for each of those, deliberately. A page per suburb would say the same thing thirty times over, and the honest position is that they are all covered by the same engineers working out of the same office, usually within the same week. Tell us the postcode.