Section and Elevations

Here is a long section through the proposals with the front and rear elevations added. You can see how the existing ridgeline is preserved and the extension forms a flat roof behind this. The second floor is timber frame with structural steel beams providing the main support back to the party walls. The exact form of the windows has changed since these drawings were done for planning. Incidentally, I'm not sure that you could do this now under permitted development-the new rules insist (since last October) on setting back any dormers from the boundary and eaves. The Planning Portal has some useful guides and tools for assessing terraced houses and what needs permission when you are considering extending. These would have been handy when the regulations were changed!

The Plans

I had a few requests from (mainly) architect friends to put the plans up so here they are. These are the ones that went in for planning.

Starting on the ground floor, the mess that is the bathroom and store disappear, and allow the living room to expand and provide a utility and cloakroom space. On the first floor the box room becomes the main bathroom, and on the 2nd floor there are 2 new bedrooms, some storage and an en-suite appears.

It all sounds quite simple when put this way, but I've managed to spend about 3 years getting to this stage. Some of this was just spending time on other options that since fell by the wayside, and of course getting the finance together took a while. The drawings reflect this, and have a lot more detail than a normal set of planning drawings, simply because I've had time to think through the construction and refine the details.

In future posts I'll walk through each of the spaces and provide some rationale for why things are the way that they are. Some of the spaces have changed internally since then, and I also had a rethink on the garden. Currently I'm waiting on the structural engineer to finish work and then no doubt some other things will change as well.

Quieter in the 19th Century?

Having been woken up really early all week by the children (roll on BST), I thought it might be a good time to talk about sound-proofing. First the science bit!

Sound is a series of vibrations that pass through everything around us which we hear by our ears picking up these vibrations and resonating. It obeys the inverse square law, so if someone is making a sound, its energy (not its loudness) reduces by the distance squared. Sound is generally measured in Decibels (dB) which reflect perceived loudness (I don't have the textbook around right now so the maths will have to wait - but from memory this is an average logarithmic scale for a certain sound frequency- which in real terms just means a figure which can be added easily so that if a sound is say 50dB and a wall has a sound insulation of 40dB then there will be 10dB getting through it).

When sound hits a material surface it can do three things: reflect, absorb and transmit. The reflection bit is what makes spaces echo and reverberate. The absorption is essentially the amount that a material deadens the sound (resulting in a very small amount of heat), and the transmission is the amount of sound that gets through. The energy of all three adds up to the original sound energy at the point it hits the surface.

In a house we are usually concerned with one or two sound problems. Internally there is the noise (unwanted sound) from adjacent rooms (talking, music and impact noise) and externally in an urban area there are things like traffic, aircraft and parties across the road. Generally most domestic buildings deal with these in two ways: adding mass and sealing openings.

Adding mass or weight to a wall or floor tends to absorb more mid and high frequency sounds like speech. Impact noise has to be handled by separation, so a wooden floor surface, for instance, will be isolated from the structure below it by rubber pads and fixings that stop the sound of kids throwing heavy objects around coming through to the rooms below. With a young family you usually need to hear things going on like this so most people in a single house would not bother with impact noise except in local areas like around the washing machine (also this is expensive to retro-fit). Brick walls are already pretty massive, but timber frame walls usually need beefing up. Conveniently the insulation for this also acts as a good thermal break as well. Incidentally the best sound insulation for this tends to be different from the best thermal insulation which is normally foam based (lots of air not much mass).

Openings such as windows and doors are the main weak point in the strategy of adding mass to an enclosure. There's not much point in heavy walls if the door is open and lets all the sound through. Internally this isn't usually an issue as long as the door is not too light-weight. Where there are particular problems (washing machines come to mind again), a heavier door with neoprene seals around the frame should suffice. The seals stop the sound travelling through the air gap.

Externally, brick walls are pretty good at reducing sound, and the main problems occur around windows. Some of this can be dealt with by draught-proofing them which again seals the air path, but in extreme cases it is necessary to use double, triple or even secondary glazing to reduce the noise from outside. Again there is some overlap here with thermal performance, but the properties of sound mean that the spacing of glass separation becomes more important. The ideal separation (again from memory- the idea here is that the sound bounces around in the gaps between the glass and loses energy before getting out into the space beyond) is around 200mm so this usually means secondary glazing to shield against loud noises like aircraft and traffic.

So in the case of our house the internal strategy will be to beef up any internal timber walls with sound insulation, use heavier doors in circulation areas (onto the stairs) and do our best to isolate the permanently-on washing machine (separate room, heavy door with seals and closer to keep it shut). Externally we will use high spec double-glazed windows with good seals (the aircraft noise is intermittent and the seals will take care of most of this). The external walls will also be thermally dry-lined which should improve their sound performance as well. Timber floors will be taken up and relaid to remove creaks, and central heating pipes re-fixed where loose (the kids love jumping up and down on loose floorboards near these as they make a huge clanging sound which reverberates in the floor voids).

The Design Brief

Having talked about the structure of the existing house at length, I suppose I ought to talk a little bit about what I would like to do with it during the renovation. My intention is to retain the period features where possible and to repair the existing structure as needed. As you might have guessed from the previous posts I will be replacing the UPVC windows, and possibly the front door (single glazed and badly fitted). Most of the existing roof will be getting replaced as well - although the front elevation will be similar to how it is now with the addition of some rooflights.


The layout on the ground floor (existing plans are shown above) is a result of the house being used for bedsits in the past and the old kitchen is currently the bathroom with a store/ WC sat in the middle. So the main aim here is to get the bathroom back upstairs where it belongs - giving more space to the living area. Of course this then means losing a bedroom on the 1st Floor. In order to keep the number of bedrooms and generally create more space we will be extending up into the roofspace (from the existing ridge backwards). The kitchen is also past its sell-by date so this will be replaced.


The result of the extension into the loft is that the hall stair will need to be enclosed and all the doors from habitable rooms (bedrooms and living room) onto the stair and landings will need to be of fire rated construction (FR30). This accounts for pretty much all the existing doors being replaced (none of them are original anyway). Another implication of this is that the plumbing will now have to extend up another 2 floors, so some duct space will be necessary and possibly a new boiler will be needed.


In the course of doing all this, most of the electrics will need upgrading/ replacing, and we will be taking the opportunity to add things like internet access and TV aerial points where needed. One bathroom will be stretched as the kids get older so an ensuite is planned for the new 2nd floor, and a cloakroom will be added on the ground floor. We will also try to add some sound insulation between the floors as we go.

Suggestions

As I'm new to the blogging world, if you have any suggestions for the site, or think that the information or layout could be improved, please let me know.

Its beginning to dawn on me that this blog is going to need lots of diagrams and sketches (just like the real drawings!), since the web is not great at displaying large architectural layouts. I think that it may also need to be organised differently to allow people to drill into the information here as it builds up and find the links to other sites as I add them.

Right now I'm concentrating on documenting the house, so that people can gain a basic understanding of the existing structure and why things are the way they are. Some of these posts will change as I think of better desciptions or add better graphics. Later on, the plan is to discuss the implications of the current building's structure when trying to meet modern standards and regulations, and perhaps come up with some general solutions.

Timeline Prologue

Reading the previous post I realised that a bit more background information might be useful.

We bought the house just before our daughter Caroline was born in late 2001. The idea was to move in at least 3 months before she was due, but the mortgage surveyor insisted that we get some damp-proofing done before completing. The company (recommended by the estate agent - no longer recommended by me!), proceeded to do the work, got it wrong and then didn't reinstate the plaster or skirtings that were lost in the process. In the end it took 4 visits spread over about the same number of weeks to get the basics of the damp proofing done (drilling and injecting into the brickwork) and the plasterwork is still hanging off in the living room 7 years later. The damp proofing itself has a 10 year warranty, so even though the plaster might be off the walls will be dry - haha!

The living room "damp" was described by the first workman as the "worst case of wet rot that he had ever seen" with loads of tendrils pushing out the plaster on the inside of the wall. In the end this turned out to be the roots of next door's climbing plant which had grown right through the somewhat powdery mortar and bricks! This still needed to be fixed of course but we were relieved that there was no rot. Another week or two went by before they could visit again.

In the end we managed to move in about 3 weeks before Caroline was born, and haven't really stopped since. Minor bits of DIY have been done but all the major stuff has been put off in anticipation of extending later on (of course at the time I didn't think it would take quite so long).

The next summer I got organised and did a quick survey of the house and started to draft this up in Autocad. I guess this part took about a week. Then the design work started........

Timeline

So, where is it up to?

Well, I managed to get a permitted development certificate in September, after a lot of juggling volumes to get it under the maximum of 50m³ over the original pre-1948 volume of the house.

This was complicated by the existing rear extension (mid-1980s) and my initial assumption that the 1898 outhouse (shown on the original drawings for the street) would be included in the calculation. But the council decided that I would need to prove that this had actually been built (archaeology of footings?) and only let me know that this was the case 1 day before the deadline for submission of amendments.

In the end I had to do a very detailed volume breakdown, but this was preferable to having to do a full planning submission. Currently the push is on to get the working drawings completed. First priority is to sort out the structure, closely followed by the specification and schedules.

Part of the reason for getting this blog going was to compare notes with other designers and owners about what works and what doesn't in terms of specified products and design solutions.
Whilst it is fairly easy to trawl the net and get a complete overdose of production information from manufacturers, there are surprisingly few examples of extended terraced houses shown online (apart from on estate agents sites of course). As an architect I find this really surprising since these are amongst the most common form of housing in the UK.

As this blog progresses, I intend to pick apart the various bits of the building that I'm thinking about and post some of the more helpful links to publications, web sites and professional bodies, that deal with those elements. It's also likely that I will have to include a rant section as well (there are a few of these that I'm storing up).