Withington Co-operative Eco-house - sprinklers

First fixing

Robert — Thu, 25 Jul 2013 20:35:35 +0000

I haven't updated the blog for a while... things have been progressing though. The sprinkler first fix is done, and the electrical well on the way. WIth the electrician in particular, it's a challenge to make sure people don't just put their pipes/cables wherever there's an available route now, without considering the other elements of the design (especially the insulation!). But everyone on the job seems to respond positively when I point out to them, as I regularly do, that something is in the way and needs to be moved or changed - for which I am thankful, because some people might be more challenging in such situations.

The builders have also done some miscellaneous brickwork and joinery items. All the studwork for the suspended ceilings and partition walls is now in place. Some more ripping out has been done; there's now a large mound of waste material in the garden, and the builders are complaining that the United Utilities work on the street is preventing them getting a skip in.

Joist sockets (and sprinkler heads)

Robert — Fri, 12 Jul 2013 17:37:44 +0000

One of the issues with internal wall insulation is that joist ends which are set into sockets in the brickwork are at increased risk of decay due to condensation developing on the cut end of the timber (see article for more information).

Fortunately, as our house is mid-terraced and the joists span between the party walls, we only have to deal with this issue in one area - the bay window. Today the builders removed the floorboard and joists within the ground-floor bay:

The next time the brickies are back on-site we will make up the socket holes, and then fit 45-degree joist hangers, which will hold the joist ends clear of the wall, within the insulation:

Meanwhile, the sprinkler first-fix is progressing. This photo shows one of the heads in position, with pipe run within the suspended ceiling void (the red cap is temporary, for the duration of construction works):

The old light-fitting to the left gives a sense of scale.

The sprinkler guys finished at lunchtime (as they always do on Fridays!) and left the floorboards up in the room which I'm using as the site office, which I thought was a little inconsiderate!

The window company haven't got back to me, and I forgot to chase them; first on the list for Monday.

Starting sprinkler installation

Robert — Thu, 04 Jul 2013 22:57:26 +0000

Today was the start of the sprinkler installation. The sprinkler guys apparently start at 7:30am(!), and finish at lunchtime on a Friday. By the time we'd gone through all the pipe routes etc on-site, they didn't get that far in to the job on the first day. But so far, so good.

Meanwhile, the main contractors have been working on the roof, which is coming along nicely. The have asked if their brickie can work on the chimney on Saturday, so I shall have to let the neighbours on the side where the chimney stack is know about that.

I'm away at the Mid-Wales Housing Co-op Gathering this weekend.

Roof finial

Robert — Thu, 27 Jun 2013 20:13:00 +0000

Sprinkler guy came back to the house with a revised drawing, everything has now been agreed and they will be doing first fix a week tomorrow (Fri 5 July). He also brought sample ceiling- and wall-mount sprinkler heads, not just for me to see but also to be left on-site for other tradespeople to be able to look at. I have to say the communications and customer service from the sprinkler company has been excellent throughout.

Unfortunately I can't say the same about the window company. At the last meeting we agreed their joiner would make an appointment with me to come back on-site to measure up etc. I'd had no contact for 2 weeks, so phoned them on Tuesday - person I spoke to didn't know anything, person I had been dealing with was unavailable until today. Phoned again today asking for that person, he was unavailable to speak to me and neither was the joiner who has been assigned to my job. Later in the day I got a brief email giving next Tuesday as the appointment day (no time specified). I wrote back asking what time and also expressed my concern at the lack of communications, and why this is unsatisfactory for this project.

Meanwhile on the roof, all the Velux openings have been trimmed out now, but we're waiting for the windows to arrive. The builders asked me a question about how to fix the insulation (given its larger than average thickness), which indicated to me that they might need some technical support when we come to doing the insulation. So earlier this evening, I phoned Pete, the guy who designed the thermal envelope specification, to see if he could come to the house for a day to work through this with the builders.

At the front of the gable there was originally a ridge finial - still to be seen on neighbouring properties. Some Googling lead me to this website, where believe it or not this guy specialises in making reproduction finials - amazing what you can find online! This one is a close match to the one our house would have originally had:

People think I'm a little bit crazy putting so much emphasis on details like this, but what's the point of working on a Victorian/Edwardian house if you're going to ignore its architecture? You might as well do a new-build Passivhaus, and save yourself an awful lot of hassle.

A day of dealing with various things

Robert — Wed, 19 Jun 2013 20:53:00 +0000

Set up a basic site office in one of the bedrooms - desk, chair, whiteboard, drawings on wall.

Had another meeting with the sprinkler company - pipe runs etc pretty much all worked out, and agreement for first fix to start a week on Monday (1 July).

It's awkward to get sprinkler coverage in rooms with sloping ceilings (as we have on our top floor), and as sprinkler coverage isn't required in rooms less than 5m2, I came up with the idea of making the top floor bathroom slightly smaller, to get it under this size threshold (it seems pointless to have sprinkler coverage in a bathroom, but at the end of the day we need to say we have complied with BS9521). This would necessitate omitting the bath from the design, which I didn't see too much of a problem with - and that top floor bathroom was crowded anyway.

The rainwater harvesting system arrived (everything but the underground tank, which is being held back until we get rear garden vehicle access). I specifically wanted the header tank on-site to ensure that the joiner builds the cupboard that will be housing it to the right size. And it was a good job I did, because I found out that, including its lid, it is just a little bit too high to fit in the space between the top of the doorways and the underside of the existing ceiling - so the ceiling will have to be raised in this area. I also hadn't realised that it has a 40mm overflow.

On similar lines, I ordered two of the single-room MVHR units (Manrose HR100RS), which should be delivered tomorrow.

I called Velux technical support to try to understand their somehow rather incomprehensible code numbers; good job that I did, as the guy helpfully pointed out that a smoke vent window is required to have at least 1m2 of opening area, and none of the Velux range with a width that would fit within the existing top floor stairwell would match. His suggestion was to have two smaller windows in-line; the other option would be to adjust the stairwell enclosure (which fortunately is all timber studwork). Need to investigate this and come to a decision ASAP.

This evening I had the future occupants of the house come round and discussed various things with them - all went well, apart from the omitting the bath idea, which they didn't like. We discussed various options including having a bath in the ensuite bathroom, and having an over-bath shower in one of the bathrooms (which I really don't like, as in my experience they always leak sooner or later - structural timbers soaking up water in an eco-house would of course not be good at all!).

Obviously it's not good to be firming up and making adjustments to the design at this stage - hindsight is a wonderful thing!

Design approach: fire safety

Robert — Wed, 05 Jun 2013 21:49:01 +0000

To explain the thinking behind specifying a fire sprinkler system in the design. Sprinkler systems are common in commercial/industrial premises, and in other countries they are used in residential too - but not (yet) here in the UK. They're actually very simple - a tank with pump constantly "primed", and heads that open at high heat. False discharges are almost non-existent, and only the head(s) in the room where the fire is will open - not, as is commonly thought, the whole system. There's no complex electronic control or detection required. So they are effective and localised. The Building Regulations now acknowledge, since the 2006 edition, the validity of sprinkler systems to contribute to fire safety in residential buildings.

The Withington Co-operative Eco-house is going to be occupied by a group of six people (the co-operative part of the project is just as important as the eco-house part, but that's another story). The traditional approach to fire safety in shared accommodation (what are known in this field as HMOs) has been to treat the hall/stairs/landing area as a "protected" escape route, achieved by replacing all the doors with fire doors. The recommended measures in the LACORS official guidance on the subject [1] for a shared-house HMO of three storeys stops short of full fire compartmentation, providing that the building is "of sound traditional construction" (which ours is). And, as it happens, the Building Regulations guidance for fire safety[2] treats an HMO of up to six occupants in the same way as a normal house anyway, which gives some flexibility in how we approach fire safety in the design of this project. Confused? Well that'd hardly be surprising, since fire safety in rental housing is covered by multiple overlapping and sometimes contradictory regulatory systems!

I'd personally argue that the fire risk in co-operative shared housing is lower than in your normal HMO situation (that argument is not gone into here for reasons of space). What we're trying to do here is provide a best-practice model. So why not go with the accepted wisdom of fire doors? Well, I think that's not the best idea for three reasons:

The house still has its original "period" doors (although the panels have been hardboarded over - typical 1960s style). When restored, these will contribute aesthetically to the living environment we're creating in the building, helping it to feel more homely. This is particularly important for us as we're offering co-operative living as a viable alternative way of creating a home, not just a stepping-stone place to live until people move on elsewhere - as often occurs in student-type HMO properties. (On a related note, the LACORS guidance acknowledges the disadvantage of escape route signage: "The need for clear information should be balanced with the desire to maintain a homely environment. The excessive provision of signage can create an ‘institutional’ feel to a building, which is undesirable in premises which are people’s homes". So I'd argue this approach should be applied to doors too.)
For fire doors to be of any use at all, they need to be closed. In non-residential buildings this is achieved by fitting a self-closing device (either a box with an armature, mounted at the top of the door, or a concealed system within the hinges). This approach was previously specified in the Building Regulations, however it was found that too often occupants disabled the closers and/or propped the doors open, because having doors closing all the time was too intrusive in a domestic environment. Consequently the Building Regulations now state "Other than doors between a dwellinghouse and integral garage, fire doors need not be provided with self-closing devices". Thus the effectiveness of the whole fire-door approach could be compromised by the occupants of the building not ensuring the doors are closed; in other words, fire doors aren't a good solution for domestic situations anyway.
With high degrees of insulation and draft-proofing in eco-houses, a supply of fresh air and the movement of air around the building becomes a design issue; no longer can it just be assumed to occur ("ventilation by accident"). Whilst it's a reasonable assumption that people will close their bedroom doors when asleep, having doors open throughout the house during the daytime will encourage through ventilation and make it less likely that occupants will suffer from stale air in certain rooms.

So the design approach taken with this project is as follows:

A sprinkler fire suppression system is installed throughout the building. Instead of a fire being confined to a particular compartment within the building, the sprinkler system will actually put the fire out before it has a chance to spread. This greatly reduces the chances of occupants being trapped within the building because a fire has spread. However, there is still a danger from smoke (especially for sleeping occupants).
A full fire alarm system will be installed throughout the building, which will be integrated with the sprinkler system and smoke control system (what is known as a Grade A LD1 system). With detector heads in every room and sounders positioned so that the alarm can be heard throughout the building, occupants will be given the earliest possible warning of fire, giving the most time to escape. Although it's likely that a fire would trigger a smoke detector first, the fire alarm will also be integrated with the sprinkler system, so that release of water from the system sounds the alarm. The alarm will also be able to be activated through manual call points.
The escape route is down the stairs and out the front door. To protect this area from smoke, an electromechanically operated skylight window (supplied by Velux) will be installed at the top of the stairwell, which will be integrated into the fire alarm, so that the presence of smoke anywhere in the building will trigger the window being opened to evacuate the smoke from the escape route.

To my mind, it makes far more sense to deal with a fire by actually putting it out, rather than letting it burn until the fire brigade arrive. This design was approved by Building Control, as part of our full plans submission. It will be interesting to see how it is viewed elsewhere.

References:

1. LACORS Housing - Fire Safety guidance, August 2008

2. Building Regulations Approved Document B, volume 1 (2010 edition)

Starting off the project - and sprinkler system

Robert — Wed, 05 Jun 2013 18:39:43 +0000

It would have been a good idea to have started this blog right at the very beginning of this project. But, since that didn't happen, getting the funding through to be able to start the building work in earnest seemed like a good milestone at which to pick up instead. There's a fair amount of work gone into this project already, which I'll have to fill you in on as we go. The main things to know for now are: we've already bought a house for refurbishment (it's an Edwardian mid-terraced property in an inner suburb of Manchester); produced the design and specification of the eco-refit - which has Building Control approval; set up a not-for-profit legal structure for the project; and got the necessary funding in place (all loan money - we're not dependent on any grants).

I had a meeting on-site with the main contractor today. They want to get the scaffold up, and start work on the roof and repointing the front wall (with possible brickwork cleaning). The advantage of this approach is that they start off in their comfort zone, and I have a few weeks to get some of the more specialist "eco" stuff ordered and delivered.

Speaking of deliveries, one of my big challenges is to work around United Utilities, who have got the road closed to do a sewer replacement. We knew for some time that this would be happening; what we didn't know was that they would change their minds about which order to do the various areas in, just as we got our money through and wanted to start work! So right now we can get up as far as next-door for deliveries at the front, and we can get a small vehicle (car or Transit van) to the rear, but in two weeks' time both of these routes into the property will be blocked, for four weeks (if they keep to their schedule).

United Utilities road closure for sewer works - right outside the house

The other meeting I had today was with someone from the sprinkler company. Now I totally agree that installing sprinklers seems like a bizarre place to start with an eco-house! I'll write a separate article explaining the thinking - but first the meeting. The sprinkler guy spent quite some time on-site looking at pipe runs etc. They're expecting all holes and openings to be made for them in advance, which is something I need to go back to the main contractor about. It's really complicated to think through the interaction between sprinkler pipes (which are rigid), regular heating and domestic water pipes, electrical cables, and insulation. One particularly tricky area is the front attic room, where there's so little full-height ceiling that it's not possible to get full coverage just from ceiling-mounted sprinklers, so it looks like we will have to put one in the ceiling of the dormer - which is already a difficult area to treat because of complex roof timbers in confined space.

Dormer roof, with roof timbers exposed. This is a difficult area to treat, in every possible way!

We're going to put in a rainwater harvesting system - used for WC flushing - and the tank will be shared with the sprinkler system. Current thinking is to get the sprinkler first fix done first - so that any making good can be done in plenty of time. But this raises a scheduling issue, as the rainwater tank is big (2.4m x 2.4m) and difficult to get on-site whilst the road blockage is in place. So I realised after the sprinkler guy had left that I may need to ask them to make a separate visit to connect up the tank - or perhaps during the commissioning.

Withington Co-operative Eco-house - sprinklers

First fixing

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Joist sockets (and sprinkler heads)

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Starting sprinkler installation

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Roof finial

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A day of dealing with various things

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Design approach: fire safety

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Starting off the project - and sprinkler system

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