Category: Building Regs

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Attention to Detail

A BBC daytime programme was on earlier as I worked – “Dreamy Architects and Their Dreamy Houses” or something to that effect. My attention grew from almost 0% to 100% as the mistakes piled up:

  • Halfway through the build, the architects (there are 2 of them) mysteriously “find some more space” in the roof. No, I don’t understand that either! Anyway, the builder is upset but the customers don’t seem to mind that the architects have changed the laws of physics and increased the bill by having work re-done. (Zollikon uses 3D software to avoid this sort of expensive mistake)

  • On another build, the narrator tells us that tonnes of cement are being poured on the ground to improve construction vehicle access. Really? That would be more than a little odd. The accompanying pictures show concrete being poured – much more sensible! (Zollikon tries to use the correct terminology)

  • Back to the first build, and the stonemason (40 years’ experience) has not put an overhang nor drip edge on some coping because ‘it wasn’t in the drawings’. The architect (also 40 years’ experience) says it was. We don’t get to see the drawings… The architect puts his foot down and the work is ripped out and re-done. He visits once complete and seems very happy, even though the stonemason has (again?) not followed the drawings. The cameraman is studiously avoiding a wide shot of the wall and the changed detail, but I manage to pause on one camera pan and see why. The coping verge is too narrow and the end drip simply pushes water onto a bulging stone below. Result? Exactly what the architect said he wanted to avoid – a lovely, new, expensive, natural stone extension, with a mouldy green wall. (Zollikon advises minimum verges at the approved 38mm, with drips for coping and advises customers on material selection on sheltered and tall walls susceptible to damp and stains.)

I once turned down a request to appear on a Phil Spencer programme to give my expert opinion on a possible loft conversion because I was relatively new to the job at the time and I would studiously double and triple research and check every detail possible into the small hours in the privacy of the office before passing comment. It wouldn’t worry me these days – judging by the low bar for TV, perhaps it shouldn’t have worried me then.

Update:
Later the same day, ITV’s prime time “£10k Holiday Home” featured a very attractive kitchen log burner stove, with timber cabinet touching the burner’s sides and a lovely wooden worktop touching at the top. Just one word –

FIRE!!

Please be very careful when listening to TV advice or trusting any one source.

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Continuing Professional Development – Ventilation

Just back from a CPD training session on ventilation organised by the new-ish outsourced building control function now serving several local authorities in the South East. On offer was a new product to eliminate damp and mould – a loft fan which pushes dryer air into the landing/hallway below and into adjoining rooms via 10mm gaps under doors.

I can see this working better with warm roofs and where, for example, there might be an issue with tenants switching off extractor fans and blocking passive vents. Noise sensitive situations might benefit as well. Because this solution provides positive air pressure, this could also help where solid fuel burners might otherwise bring required powered extractor fans into conflict with building regulations – with particular regard to carbon monoxide poisoning. The installation work is minimal compared to drilling multiple wall cores and running additional circuits, particularly in a retrofit/upgrade situation.

Another product on show logs the number of hours the fan has been used, so (sometimes false) claims about damp building problems can be verified…

These products are not optimum for every case and there are lots of other ways of meeting the building regulations on ventilation, but it is always good to have multiple options available.

The next CPD is on fire mist sprinklers – cheaper, less damage, fit in a GU10 sized hole – another great string to the bow in the continual quest to ensure that buildings are efficient, comfortable and safe.

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Past Projects

Zollikon has been around for a few years and worked on a large number of projects. The following examples are listed to give an idea of our experience:

  • Design, planning permission and building regulations for renovation, extension and conversion of derelict bungalow to house, sympathetic to Grade II listed neighbour – Zollikon success after client’s previous failure.

  • Extension and conversion of existing building to 7 flats – building regulations/plans for stalled project, including subterranean, to enable sale.

  • Several rear extensions using new Neighbour Consultation Scheme to double normal permitted development rights (PDR) limits.

  • Double and triple planning application strategies to benefit from both permitted and consented planning on the same building.

  • Conversion of historic stables to habitable – design, construction/building regulations detailing, build management including full under-pinning, tanking, restoration of lime mortar, structural reinforcement.

  • Multi-disciplinary case management (planning, barristers, design, structural, Party Wall) for multi-million town centre flats project involving defective title deeds, legacy planning and multi-party negotiations

  • School playground/outdoor classroom design, plans and 3D visuals to assist students with special needs (pro bono)

  • Architectural plans, legal searches, joint venture business plan and multi-party negotiations to treble value of town centre plot to create up to 25 flats.

  • Large kitchen/living/dining parapet extension, en suite, porch and extensive landscaping for substantial house – design, planning application, construction detailing.

  • 19 new build one and two bedroom flats – feasibility study.

  • Successful negotiation with council Building Control Department to allow 5m x 4m rear extension as ‘porch’ to enable building regulations exemption.

  • Extensions to two flats – design and planning application.

  • Double dormer loft conversion within Permitted Development Rights, with fire curtain protected route option through open plan ground floor.

  • New-build 2 bedroom detached bungalow – planning inspectorate appeal and land acquisition consultancy.

  • Manse loft conversion with L shaped dormer to create 3 new bedrooms, bathroom and study. Also orangery, conservatory and open plan remodelling. Planning permissions, design and building regulations.

  • Achieving Building Control completion certificates on extensive structural, thermal, electrical and other works to six dwellings within 2 months (following several years of unsuccessful attempts before Zollikon’s involvement).

  • Successful Listed Building Consent for loft conversion, stairs and windows on Grade II cottage.

  • House extension and conversion to 4 flats/25 rooms – design, successful planning appeal, build management.

  • 1800m2 industrial units – business development consultancy and plans to maximise return.

  • Bungalow extension, interior alterations and crack investigation – design, building plans, structural engineer liaison.

  • Front extension to lounge and porch (builder’s own home) – design and planning application.

  • Two storey side extension into loft (different builder’s own home), including new log burner and en suite – reworking existing loft plans, construction/building regulations detailing.

  • 100 seat restaurant dining area and kitchen layout, licence application.

  • Joint venture, finance, plans, building regulations, build management consultancy for new property developers.

  • Plans, planning permission, building regulations, build checking for rear extension covering entire back garden in conservation area (subsequently recommended for and achieved planning for two storey extension in same conservation area, subsequently recommended for third extension in same conservation area…)

  • Design, planning and building regs for eighth customer in the same road completed! – all word of mouth recommendations.

  • Extensive project to combine two flats into one house, convert loft and add double side dormers and lower ground floor extension, remodelling to include: extra bedroom, extra en suite, extra toilet, extra utility room, 2 new offices, reworked bedroom, new bathroom, new open plan kitchen-diner-family room, 3 new staircases. All achieved within permitted development rights.

  • Extensive remodelling and extension to house forming one wing end of Grade II listed 18th century stately home in AONB, following Zollikon success on the other wing’s sister house.

  • Plot-finding, site acquisition, topographical survey, plans and planning application for 5 new flats on vacant urban brownfield site.



Perhaps your project contains elements similar to one or more of the above examples? Perhaps you have a new challenge for us – we love overcoming challenges! Zollikon has a lot of experience, skills and hunger to succeed for our clients. We look forward to helping you.

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Loft Stairs

There are several great advantages to converting a loft compared with a ground floor extension:

  • no costly new foundations needed (subject to checking)
  • no new roof needed
  • no wasted garden space
  • upstairs bedroom/s
  • loft bathrooms/en suites can make good use of eaves
  • upgrading roof insulation benefits the whole house
  • generous planning PDRs can reduce planning costs and risks

So, lots of good reasons to consider a loft. These pluses need weighing against issues such as the need to consider fire safety, structural reinforcement and noise transmission, but so long as the basic height needed is there, a loft is a definite possibility.

One issue that does need consideration at an early stage is access – stairs.

Issues include:

  • Stairs and access to them, will cost space on the first floor
  • Placing loft stairs over existing stairs can be an efficient use of space
  • Stairs typically need to arrive in a high point of the roof to provide enough headroom
  • Building regulations stipulate a maximum stair pitch of 42 degrees
  • Each tread must have a minimum of 2 metres clear height above, except loft stairs, which may have a centre-line height of 1.9m with a lower edge of 1.8m to allow for a sloped roof above
  • Loft staircase headroom can be helped by Velux/roof lites and dormers
  • There are also minimums for stair landings and rules governing door openings near stairs
  • If the stairs create accommodation on a third floor, enhanced fire safety requirements and protected route escape rules can be met using a whole range of tools (e.g. linked smoke alarms, heat detectors, fire doors, intumescent products, fire boards, fire curtains and sprinkler systems)
  • Carpeted loft stairs will be quieter for nearby bedrooms
  • Winds and low ceilings will impact on moving larger furniture
  • For minor breaches, building inspectors (local authority building control officers or approved independent inspectors) have some discretion to decide what they consider to be a safe staircase
  • There is no rule governing the minimum width of private staircases
  • Risers and treads must be consistent – adding or removing height to the bottom step to make up for an error is not OK!
  • Spiral staircases and space saver (alternating treads) stairs can be an option.
  • If buying a second hand staircase, please consider/remember (or Google!) the 100mm sphere safety rule.

And so on.

Of course, you do not need to learn all of the above; Zollikon is here to take the technical load off your shoulders and assist as you specify your priority and design preferences.

Zollikon uses 3D CAD software which is a huge benefit when dealing with tight spaces, minimum heights, rising steps and sloped ceilings. We can add thickness to loft floors and ceilings to show the impact of reinforcing and insulating work needed in loft conversions. From your point of view, you will get to see your staircase, floor, walls, ceilings in 3D from any angle you like. We can even populate the model with people of your height to help understand the dimensions.

The sort of experience, expertise and software that Zollikon offers will go a long way to making a complex subject user-friendly for you. Loft stairs – tick.

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Velux Rooflight Tips

A few random thoughts and tips on the subject:

  • The lowest angle a standard opening rooflight can used at is 15 degrees – lower and it could leak. Below this angle the window can be placed on a sloped upstand. Or there are plastic bubbles and domes. And now glass curves. Pop-ups. Or architectural glass. Or a lantern. Sliding glass. And possibly more besides…
  • A series of rooflights is more expensive and less efficient than one big one, but the visual impact of several can be very striking – think of rows of downlights.

  • Take a look at Google/Bing images and supplier catalogues for some inspiration. There is often no need to reinvent the wheel.

  • Roofs that meet structural and thermal building regulations can be very thick, especially preferred ‘warm’ roofs where the insulation is above the rafters or deck joists. By the time floors have also been upgraded, loft conversions can be short on headroom – a potential show-stopper when trying to meet building regulations regarding headroom above loft stairs. Happily, rooflight glass is above the outer skin of the roof, potentially giving 8, 10, 12 inches of extra internal height – very useful for ‘pinch points’ and sometimes enough to make the impossible, possible.

  • Generous use of rooflights can lead to failure to meet overglazing regulations. Zollikon has been able to avoid this potential show-stopper using off-setting or whole-build calculations.

  • A flat roof (technically 10 degrees or less) still needs a slope, to gently migrate water away and avoid puddles. Internal ceilings (that aren’t sloped skeilings) are normally horizontal. Slope outside + flat inside = diminishing reveal. Unless… a compensating upstand or multi-pitch roof and internal gutter/valley could avoid the issue.

  • Privacy can be an issue with rooflights. 3D software can be helpful in analysing any potential problems and solutions.

  • Or a sun tunnel? Or a clerestory? Glass blocks?

  • Long poles are available for opening and closing high rooflights. As are remote control electric rooflights and blinds, with rain sensors…

  • And finally, rooflight or roof light? Or anyone for skylight?!
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Kitchen / Diner Log Burners

Zollikon has worked on several projects where customers have wanted a Ground Floor rear extension to their kitchen, to include an open plan dining room and sofa/TV area – a ‘Swiss Army knife’ multi-purpose family area. To complete the new lifestyle, a log burner is then sometimes specified – warmth, atmosphere, lovely.

But the placement of a log burner in a room containing a kitchen brings an interesting conundrum with regards to building regulations.

Kitchens must have a mechanical extractor fan. Rooms with log burners cannot have a mechanical extractor fan. What gives?!

When asked about this, one experienced Building Control officer told me that he could sign off the kitchen and a registered HETAS installer could then sign off the log burner installation. I love helpful Building Control inspectors who are happy to exercise their common sense in allowing builds to proceed sensibly. But with solid fuel burners we could be looking at noxious gases, like the deadly carbon monoxide, being sucked into a family room. I always think of my clients’ projects as though it were my family living and sleeping in the house when it comes to safety.

The solution seems to be an air vent to outside placed near the log burner to ensure that any negative air pressure from the cooker extractor fan brings fresh air through the log burner’s air vent, not gases from the log burner. If this arrangement is agreed by your building control officer / HETAS installer, it is literally vital that you make sure the air vent is always kept clear – check for leaves, dirt, plant, etc outside and carpet, rugs, cushions, furniture, boxes, toys, etc inside. Of course, by law, you must also have a working carbon monoxide alarm, correctly positioned, as a further safeguard.

While I’m in a health safety mode… especially if you have young/visiting children, please remember that log burners can get extremely hot. A guard and discouragement of running around near it when hotter than an iron would be wise precautions.

Please also only use well-seasoned (dry) wood. This reduces unhealthy and polluting smoke particulates, protects your chimney from dangerous soot deposits, produces more heat and is a lot easier to burn. Your wallet, your neighbours and the planet will thank you. If unsure about your wood supply, you can buy a moisture detector for just a few pounds.

Having said all this, log burners are fantastic features that can kick out enormous amounts of heat far more efficiently than an open fire and they are popular for good reason.

Enjoy!