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Andrew Horton

Turning a stone barn into a home

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by Andrew Horton

A derelict, redundant stone barn in the countryside can seem so appealing to developers or people who dream of creating their own home in the middle of nowhere but turning a barn into a habitable property can be a challenge. That said, the end result usually outweighs the effort involved, so don’t be put off, but you will need to find a structural engineer to help you along the way.

As consulting civil, structural and conservation engineers, we are often involved in modern barn conversion projects from an early stage so that we can complete a pre-planning structural appraisal of the building and to also produce a drainage strategy as is often required from the outset.

What is a pre-planning structural appraisal?
This will help you determine whether your vision is possible before they go to planning. We will look at the topography of the site, boundaries, slopes, trees, and other on-site features before considering the existing structure and what will be required to achieve your plans or your architect’s designs. This preliminary advice will help with project costings too, which will enable developers and contractors to price their works more accurately. Examples maybe that the original stone walls are founded at a shallow depth and would become exposed due to lowering ground floor requirements and we can identify likely measures to facilitate this.

  • Lack of foundations
  • Poor ground conditions or adjacent to water so sodden support strata
  • Walls not sufficiently tied to floors or roof
  • Missing or collapsed first floor
  • Lack of roof or alterations to existing support elements
  • Missing or crumbling stonework
  • Close to slopes or rock faces
  • Protected wildlife in residence

Support and sensitive repair
Many of the above challenges can be overcome with the appropriate support works to maintain the character of the barn while ensuring it does not fall down! Internal timber frames have become popular, but we can design new support from floors or roof to provide the necessary restraint requirements of modern building regulations.  We can undertake all the calculations required for timber framing, steel frames/trusses and floor structures.

As conservation engineers, we have a great deal of expertise in sensitive repair work to ensure stonework is maintained where possible. Where barns are built into a rock face or are close to a slope, we can discuss solutions to overcome these issues to ensure your barn is both habitable and safe.

A protected species survey may need to be carried out before you begin work – not something we do – but we can advise you on possible workarounds to accommodate your furry or feathered house mates following the survey. We set aside loft space for a barn owl in a recent conversion we worked on!

All the above may seem like an enormous undertaking but, as I said in the opening paragraph, the home you end up with will be worth it.

The vaulted ceilings, the exposed stonework, the open-plan space, the opportunity for the sensitive use of glass, and so on mean you can create a unique home while preserving and repurposing an otherwise derelict building.

If you are considering a stone barn into house conversion project and have done a web search for “structural engineering companies near me,” and found PCA, then please do not go any further! Contact us now. We will be happy to help. Also, see our recent case study on Willowplatt Barn.

Celebrating World Heritage Day 2023

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by Andrew Horton

April 18th is World Heritage Day, also known as the International Day for Monuments and Sites. To celebrate this annual occasion, PCA has been reflecting on some monuments we have worked on.

The first one for your perusal is Stoney Littleton Long Barrow. This is a Neolithic chambered tomb with multiple burial chambers, located near the village of Wellow in Somerset.  It is an example of the Cotswold-Severn Group and was scheduled as an ancient monument in 1882. The entrance appears as a lintel supported by two jambs. It is 1.1m high and faces towards the south-east.

In 2022, PCA were called in to inspect evident cracking in the lintel over the door opening. Working with English Heritage, we carried out a structural inspection of the barrow, producing a report to confirm our findings and recommendations. The Barrow is open to the public and an internal chamber with a transepted gallery grave associated with three pairs of side chambers and an end chamber. The gallery extends for 12.8m and varies in height from 1.2m to 1.8m.

Next is HMS Drake. Originally built in 1896 and grade II*-listed, this is the final piece of what was formerly known as Keyham Barracks. The clock tower at HMS Drake has been a prominent feature of the naval base and, indeed, Plymouth for more than 115 years at Drake Gate on Saltash Road.

Lastly, the grade II-listed Newton Abbot War Memorial. Built in 1920-22, it was added to after the Second World War and again following later conflicts. The First World War memorial was designed by the borough surveyor, Coleridge Dingle White, and takes the form of a column set on a substantial plinth bearing the names of the war dead on the four faces on bronze plaques. A bronze statue was added by the opening of the memorial in July 1922, which was sculpted and designed by Courtenay Edward Maxwell Pollock as a symbol of victory and freedom.

PCA involvement for both these monuments was to inspect their structural condition and give recommendations and specifications for repair.

Well, these are our top three monuments for 2023’s World Heritage Day. We hope you have enjoyed stepping back in time with us and the conservation engineering work we have carried out to maintain these historical sites.

Thanks to Linda Capon for pulling this information together for us. Until next year….

 

Can I build a property on the side of a hill?

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by Andrew Horton

If you live anywhere in the South Hams or, indeed, in other Devon or Cornish coastal areas, you already know building on the side or into a hill is possible. So many houses or apartments in this area are perched on a hillside or seem to blend into a landscape of a sloping plot.

Some of these properties may have been there for decades but we are seeing plenty of new developments that require our engineering expertise to meet both structural and aesthetic requirements.

If space allows the ground can be removed and a space left between the retained bank or slope and the new property. The bank must be protected against landslides and depending on the strata, the retaining element could be gabion baskets, stone-faced reinforced concrete walls or rock anchored mesh to support deep cut faces.

See Ferncliff as an example of this or our photos from Woodspring where we used a deep mesh-covered wall to support the land at the rear of the house, as well as the driveway and level garden.

Where properties blend into the landscape or basements need to be dug out to ensure a roofline does not exceed recommended height for the area or boundary conditions dictate, there is often no space behind. This means waterproofing will also be needed to prevent damp. Willowplatt Barn is an example of this type of project, as well as The Boathouse where much of the property was carved into the hillside.

Large scale excavations will require substantial temporary works or permanent retention schemes and these need to be considered early in the project as can often be the key to unlocking difficult sites or realising these hillside schemes.

We also devised temporary works for Clock Cottage whereby proprietary piles were used to support the existing building while contractors dug out the hillside beneath to create a new basement area.

Securing the remaining hillside and damp-proofing are not the only challenges associated with building on a slope. Access can also be challenging. Roads to hillside properties can be narrow and driveways can be awkward to negotiate so getting equipment and building materials onto site can be problematic.

Drainage too must be considered when building on a slope. Rainfall must be directed away from your property’s foundations without flooding another property or public area, often both, during construction and in the permanent state. Sewage needs to be channelled the right way too and may require pump stations to connect to higher level connections.

Building on a slope can be costly due to the groundworks, extra time, materials and expertise potentially required, but the expense is often outweighed by stunning views, extra light and landscaping options that can be gained from being on a hillside.

If you have your eye on a hillside plot that you would like to build on or a property on a slope you would like to redevelop, please do not hesitate to get in touch with us. Expert advice is always key for a project like this.

Why use insulated concrete forms for your build

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by Andrew Horton

Insulated concrete forms or (ICF) is an efficient alternative to traditional build methods, such as timber frame or brick and block, in terms of the time spent on construction and ongoing energy savings.

For the uninitiated, a timber frame build unsurprisingly sees timber used as the framework of a building or extension before affixing stud walls and an external waterproof barrier, and then applying external wall elements. The brick and block method sees internal blockwork and external walls made of brick or stone. The latter method takes longer than a timber frame construction, which can be up in a matter of days.

Quicker still is ICF. This is an insulated concrete building system that is super quick to construct. Hollow, lightweight, expanded polystyrene block components, such as the ones made by NUDURA, lock together to provide a formwork system into which concrete is poured. Basically, its LEGO for builders!

Once set, the concrete structure continues to benefit from the formwork. The 67mm layers of expanded polystyrene encases the concrete to significantly reduce the flow of heat through the wall.

NUDURA celebrates the fact that their ICF walls have “the most useful level of thermal mass,” in that their low thermal conductivity stabilises the internal temperature from day to night fluctuations and provides a largely self-regulating environment to reduce draughts and cold spots.

The result is less energy consumption thereby reducing the need for mechanical heating and cooling…which drives down costs too. Such energy efficiency is becoming more and more important as people try to lead their lives a more sustainable way. As a further bonus, the NUDURA unique folding web design is manufactured from 100% recycled polypropylene too.

With the correct detailing, ICF is an effective sound barrier from outdoor noise, is mould resistant, can withstand winds up to 250mph and is flood resistant. Tick, tick, tick and tick!

PCA has worked on multiple projects using ICF. It is particularly efficient when building basements, due to its dry and damp-free properties, but is equally effective above ground. What makes it appealing to construction firms though is that it is deigned to make building easier and faster.

And to complete the job, a whole range of external finishes can be used, including brick, render, stone, timber and cladding or a combination of any of these.

If you are considering a new-build or an extension and want to find out more about ICF, please do not hesitate to get in contact with us.

You can also contact The Fell Partnership for further information on NUDURA.

What you need to consider before fitting a bifold door – or sliding doors

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by Andrew Horton

In the last six months, fresh air has been key when it has come to gatherings of small groups of people. Even when two households were permitted to meet, these get-togethers often took place in the safety of a back garden and these meetings were clearly easier as social distancing measures went into the warmer summer months.

With six months of restrictions still to come and winter on its way, those outdoor gatherings may start to get tricky. While in England we are still allowed to meet indoors, vulnerable people may choose to stay outdoors or, at the very least, let plenty of fresh air in when they are indoors. Similar to schools having to open all the windows in classrooms.

Bifold or sliding doors make an indoor space feel part of the outdoors and certainly let plenty of fresh air in! They have become a popular replacement for French windows as they offer floor to ceiling, wall-to-wall natural lighting and help to bring the outside in, especially if you have a level threshold between your home and your outside space. Perfect for these COVID-19 times!

You can even get bifold or sliding doors that meet at a corner to give you light and space from two sides of your property. However, in the words of UK bifold door manufactures, Origin: “Hiring the services of a structural engineer is imperative if you plan to have a corner set of bi-fold doors installed. A structural engineer will survey your home to ensure it’s structurally sound and suitable for corner bifolds.”

As you would expect, you cannot just knock a hole in the wall and get cracking…even if you just want bifold or sliding doors for single wall and social distancing is making you feel a little hemmed in!

You will undoubtedly need a beam, or suitable lintel, to support the load above the new opening where the bifold doors will fit. External walls are an integral part of a building’s structure. They can be load-bearing walls, so it is important to understand what they are supporting, e.g. roof, floors and walls above, and we can then advise on the correctly sized beam or lintel to use so the load can be transferred adequately into the adjacent walls, as long as these are structural and have sufficient bearing and foundations.

Specialist door installers usually just come and fit the door, so you will need a builder to create the opening. Before you do this though, you may want to seek out our advice to ensure your home is suitable for a bifold or sliding door. Do not worry, most will be, but it is best to check before you buy!

Planning permission is often not required but advice from an architect or the local planning authority should be sought in the first instance before you make any decisions, especially when installing bifold or sliding doors where the house is listed or in a conservation area. You will need building regulation approval, however, and our involvement and design calculations and/or plans will help gain this.

If you are considering bifold or sliding doors, or any other alterations to help keep the fresh air flowing in the next six months as social distancing continues, then please do not hesitate to get in touch with us.

Dealing with landslides and collapsed walls

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by Andrew Horton

Wet weather earlier this year saw PCA called in to advise on how to rectify various landslides and collapsed walls…some of which have not yet been rectified or repaired due to lockdown.

It is not surprising we have saw so many in 2020 with February being the wettest month in the UK since records began in 1862. The UK received an average of 209.1mm of rainfall, which was 237% above the average for the month compared to Februarys between 1981 and 2010.

Such a volume of water can create hydrostatic pressure or causes surface water run off when the ground is saturated. These conditions contribute to landslides and collapsed walls, and flooding in areas of poor drainage. Erosion can also occur caused by weather, tides, rivers, etc.

Some walls are also at the end of their life with old mortar that simply gives out. Others are boundary walls where the ground has built up behind them overtime to, well, breaking point. Again, poor drainage, or lack of drainage, can contribute to the wall failure.

Whether your wall has already collapsed or an area of your land has started to shift or you are worried how the next bout of heavy rainfall will affect your property, we can help. We will assess the problem and will come up with varying solutions to replace your walls and shore up land.

We can also work within the standards required if your landslide or collapsed wall infringes on a highway and, where appropriate, we can work with loss adjustors if an insurance claim is warranted.

Please do not hesitate to contact us.

PCA – serving the needs of Cornwall clients

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by Andrew Horton

While we have been based in Devon for 40 years, we have worked for most of these years in neighbouring Cornwall too.

As our illustration shows, we are currently working on numerous projects throughout the county, ranging from National Trust properties to commercial projects, alongside architects and contractors to help create bespoke homes for private clients.

Our engineers can often be seen crossing the Tamar Bridge to visit these sites and new schemes, so please do not hesitate to contact us if you have a project in Cornwall that may benefit from our structural, conservation and civil engineering expertise.

Cold weather working

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by Andrew Horton

With November shaping up to be the coldest since 2010 and the Met Office already predicting the coldest winter for 50 years, it is worth noting the constraints of cold weather working.

While locally we rarely experience prolonged periods of freezing temperatures, it is important that specifiers and contractors are fully aware of cold weather working.

This may include protecting newly-laid concrete from frost, avoiding laying masonry units in falling temperatures (below or likely to fall below 2°C) or using suitable materials for site-mixed concrete. Temperatures should be checked throughout the day on a thermometer.

Although the temptation is to pop your hard hat on top of your woolly hat, remember that this may compromise the fit of the hat. Manufacturer-approved head warmers are available that can safely be worn under a hard hat, so you still get a good fit for your safety helmet without compromising its effectiveness.

If in doubt, please do give us a call and PCA can advise as necessary and ensure any structural works are not affected by cold weather.

New entrance and new wall to improve access

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by Andrew Horton

This residential project required a widened entrance and replacement garden wall due to the dilapidated state of the existing masonry wall constructed from random rubble.

The existing narrow entrance to this property was restricted further to a substantially leaning stonework wall, so planning was obtained through architects Andrew Lethbridge Associates to round off the entrance and improve access with a wall suitable to retain the garden.

PCA worked with local landscaping contractor Andrew Rhymes, of TimberJack, to construct a hollow block, reinforced, concrete wall with a stone face to replicate the existing structure and provide a far improved entrance.

We can help with projects big or small and always keen to work with local contractors and architects to give the client a superbly finished scheme such as this.

Pitched roof for a garage conversion

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by Andrew Horton

Garage conversion beforeWhen our customer bought a split-level bungalow in Kingsbridge, it was always their intention to convert their integral garage to create a larger space for a kitchen-diner, but they did not want it to look like an obvious garage conversion.

Working with PCA, Simon French (RSL Surveyors) and local builder Tristan Couch, from TJ Couch Building, a pitched roof was added to the conversion to help it blend in with the rest of the property.

Garage conversion steelThe extra load of the roof and new 3-metre window meant a new steel beam was required to support the timber-framed extension and new-look roof line.

Existing composite trussed rafters had to be cut back with strengthened ends that could be supported off the new steel and maintain a level ceiling from the old section of house into the new extension. PCA helped progress with ad-hoc site visits as required to ensure the builder was not delayed at any point.

Garage conversion internalOur customer John Moore said: “PCA helped us realise our plans for our home. It is very easy to imagine what you want to achieve but there is always more to it than the building work. We are grateful for Andrew Horton’s advice and used PCA again when we extended the back of the house too.”

If you have a building project in mind, you may require advice on ensuring your plans are structurally sound. Your architect, surveyor or builder should advise you to seek out a structural engineer. If you have any doubts, please do not hesitate to contact us.