Extension / Garden Room

gym11

Doozergirl said:

gym11 said:

We are currently in a house with an external garden room. Ours is insulated walls and roof, with glass walls on one side. When we first moved in we really  liked it but have definitely changed our opinion now!
It winter it's far too cold to use unless we run the electric heater which is then really expensive. The minute you open the door all the heat escapes into the garden so you then have to heat it up again.

In summer it's unbelievably hot. We have to have full length blinds permanently closed and then leave the door open - even then there have been afternoons in the last week or so when I've had to give up working in there. Last July/August we couldn't use it as the temperature was much constantly above 30 degrees!

When it rains it's really noisy. It's also actually a bit of pain having to walk across the garden to get to it. Especially when it's cold or wet or the ground is slightly damp. I always feel I have to put proper shoes on (not slippers!) as otherwise your feet get wet! Lighting is also something to consider - if you use it in the evenings when it's dark you need a well lit path back to the house otherwise you can easily fall over (as I've discovered!!)

We also find that we get a LOT of people staring into it when they walk past the garden. Might be less of a problem with a more private garden but it certainly feels a bit of a goldfish bowl at times.

Overall, whilst it looks impressive I'd say it's really not very practical - we dislike having to carry stuff back and forwards particularly (Laptops, Tablets etc) as the room is too hot or cold to leave electricals safely without risk or damage - just something to consider if you wanted to put teenagers and electrical equipment in one.

How much insulation do you have?  It doesn't sound like you put enough in, especially if the roof is noisy as well.  

We didn't build it, it was here when we moved in. But it is definitely a purpose built garden room with insulated walls and roof. The double glazing is very good quality (better than on the house) but the reality is it's a box outside with 4 external walls. So although it's better insulated than a conservatory it basically has the same issues (temperature/noise). 

AdamBloke

gym11 said:

We are currently in a house with an external garden room. Ours is insulated walls and roof, with glass walls on one side. When we first moved in we really  liked it but have definitely changed our opinion now!
It winter it's far too cold to use unless we run the electric heater which is then really expensive. The minute you open the door all the heat escapes into the garden so you then have to heat it up again.

In summer it's unbelievably hot. We have to have full length blinds permanently closed and then leave the door open - even then there have been afternoons in the last week or so when I've had to give up working in there. Last July/August we couldn't use it as the temperature was much constantly above 30 degrees!

When it rains it's really noisy. It's also actually a bit of pain having to walk across the garden to get to it. Especially when it's cold or wet or the ground is slightly damp. I always feel I have to put proper shoes on (not slippers!) as otherwise your feet get wet! Lighting is also something to consider - if you use it in the evenings when it's dark you need a well lit path back to the house otherwise you can easily fall over (as I've discovered!!)

We also find that we get a LOT of people staring into it when they walk past the garden. Might be less of a problem with a more private garden but it certainly feels a bit of a goldfish bowl at times.

Overall, whilst it looks impressive I'd say it's really not very practical - we dislike having to carry stuff back and forwards particularly (Laptops, Tablets etc) as the room is too hot or cold to leave electricals safely without risk or damage - just something to consider if you wanted to put teenagers and electrical equipment in one.

I wanted to ask the same as @Doozergirl
What's the wall thickness? Any cross ventilation? Is it in direct sun all day? Ours would be (if we build it) 150mm thick celotex or kingspan insulation floor, walls & roof and I would add a small back window to get some cross ventilation going.
@Doozergirl - any answer to my 3:57pm post above would be most appreciated - (given that I mean plinth not pad foundations)... you are evidently very knowledgable about all this stuff... I am also researching pile foundations today to see if that's a viable option. Cheers all for your input.
I would like to find a way to actually extend properly if cost can be reasonable - that's ultimately the preferred option, but the back up plan of garden room is still on the back burner and I want to know if that's viable if needs must.

princeofpounds

Get a good architect who works with a planning consultant. It will cost a couple of k but you the expertise will be very rewarding and you will understand your full set of options.

In the meantime, you might want to read Martin Goodall's blog; he has written some great material on PD over the years.

http://planninglawblog.blogspot.com/

AdrianC

AdamBloke said:

Hello all - I have read a few posts here and would love to get some advice. I'll try to be as detailed as possible to save you all time in the long run.
We would like to add a single room, single storey extension to our house (family has grown to the point that we need it now). House is semi detached and size isn't an issue in terms of area covered or height restriction etc as the garden is of a fair size. I have discussed at length with local planning who have been very helpful in telling me what's not possible and what would be frowned upon were I to make the application for certain ideas.
The crux of our problem is a beautiful tree on public land about 1m outside our fence and 2-3m from the corner of the viable plot. We love the tree for it's shade and character and so don't want to affect it anyway, but it does mean that without super deep foundations a 4x3m extension of the standard brick & block type is a no go. The second issue is that this is not an expensive house or area and so throwing a considerable amount into the extension would not be sensible budget-wise or as an investment. I suspect a 30 grand extension would probably add at most 20 grand to the house price. We're not doing this as an investment (it's for us, so profit isn't so important) but it would be nice not to spend considerably more than it's worth in this area (ex-council houses on outskirts of town).

Think outside the box a bit...

Would putting that £30k into the pot make a move to a bigger, more suitable house possible?

Doozergirl

AdamBloke said:

gym11 said:

We are currently in a house with an external garden room. Ours is insulated walls and roof, with glass walls on one side. When we first moved in we really  liked it but have definitely changed our opinion now!
It winter it's far too cold to use unless we run the electric heater which is then really expensive. The minute you open the door all the heat escapes into the garden so you then have to heat it up again.

In summer it's unbelievably hot. We have to have full length blinds permanently closed and then leave the door open - even then there have been afternoons in the last week or so when I've had to give up working in there. Last July/August we couldn't use it as the temperature was much constantly above 30 degrees!

When it rains it's really noisy. It's also actually a bit of pain having to walk across the garden to get to it. Especially when it's cold or wet or the ground is slightly damp. I always feel I have to put proper shoes on (not slippers!) as otherwise your feet get wet! Lighting is also something to consider - if you use it in the evenings when it's dark you need a well lit path back to the house otherwise you can easily fall over (as I've discovered!!)

We also find that we get a LOT of people staring into it when they walk past the garden. Might be less of a problem with a more private garden but it certainly feels a bit of a goldfish bowl at times.

Overall, whilst it looks impressive I'd say it's really not very practical - we dislike having to carry stuff back and forwards particularly (Laptops, Tablets etc) as the room is too hot or cold to leave electricals safely without risk or damage - just something to consider if you wanted to put teenagers and electrical equipment in one.

I wanted to ask the same as @Doozergirl
What's the wall thickness? Any cross ventilation? Is it in direct sun all day? Ours would be (if we build it) 150mm thick celotex or kingspan insulation floor, walls & roof and I would add a small back window to get some cross ventilation going.
@Doozergirl - any answer to my 3:57pm post above would be most appreciated - (given that I mean plinth not pad foundations)... you are evidently very knowledgable about all this stuff... I am also researching pile foundations today to see if that's a viable option. Cheers all for your input.
I would like to find a way to actually extend properly if cost can be reasonable - that's ultimately the preferred option, but the back up plan of garden room is still on the back burner and I want to know if that's viable if needs must.

I don't think it has enough insulation.  If it were solar gain through the windows causing it to overheat then you'd expect it to be warm in the winter, still.  150mm of solid insulation should be nice.  

Re: a plinth 'foundation' Because these buildings don't need to meet building regs, they don't build them to regs.  The easiest way to save is to put in a cheap foundation and cross fingers.  In many cases they will
be fine, but it is next to a tree, still.  Subsidence will show itself in a number of ways, where it's a tilting, a cracking across the floor or the walls.   This started with the issue of building near a tree and the only way to counteract potential movement is to get your footing deep and solid.  

Piling is really expensive.  Much more than an extra metre of digging.  Trench foundations are the most common because they are the most economical. 

If you want to save some money, would you consider digging your own foundations or even mixing the concrete? 

AdamBloke

@princeofpounds - thank you very much - I'll check that out!
@AdrianC - yes - it's a discussion we've had... rather stretched at the moment - we thought if this doesn't work out (extending or garden room) then we would probably continue to save and try to look for somewhere in 3 or so years (when we would have accrued a bit more to make it worth it.

AdamBloke

Doozergirl said:

I don't think it has enough insulation.  If it were solar gain through the windows causing it to overheat then you'd expect it to be warm in the winter, still.  150mm of solid insulation should be nice.  

Re: a plinth 'foundation' Because these buildings don't need to meet building regs, they don't build them to regs.  The easiest way to save is to put in a cheap foundation and cross fingers.  In many cases they will
be fine, but it is next to a tree, still.  Subsidence will show itself in a number of ways, where it's a tilting, a cracking across the floor or the walls.   This started with the issue of building near a tree and the only way to counteract potential movement is to get your footing deep and solid.  

Piling is really expensive.  Much more than an extra metre of digging.  Trench foundations are the most common because they are the most economical. 

If you want to save some money, would you consider digging your own foundations or even mixing the concrete? 

Thank you so much @Doozergirl - that is seriously very helpful... Don't mind doing some digging and mixing concrete so we could save some there... my brick laying would be a catastrophe though!... Plenty to think about - really good to hear from real people - the internet has so much confusing and often contradictory advice that you just don't know what to follow... Some people advise belt and braces, but it's hard to know how much might be over engineering because they're linked with the construction trade so increased materials and labour is how they would always suggest things should be done and then others tell you plinths are fine, but that's because they're selling garden rooms or similar... Then there's the 'non-commital' planning officer who just seems to evade giving a straight answer to the finer points that aren't covered by the technical guidance. Everyone has a vested interest, it's just so hard to sift the facts from the bull.
That's why it is great to get an experienced view knowing that its honest because well - you have no reason not to be.
Thank you

daisyfrau

We just literally had a garden room built on ground screws. It is 1m away from a beautiful old field maple tree we wanted to keep. Look up ground screws - used extensively in Scandinavia. Much cheaper and less disruptive than concrete pad or plinths. Can be installed in a couple of hours once ground cleared and relatively level. Tree roots not a problem - v little disruption to tree.

We got our room built by Garden Spaces - they do both garden rooms and single room extensions on the same foundations. Top tip - look at their testimonials page - you can search by area/type of build etc or just scroll through. They work nationwide I believe. 

Our room is second to none - internally looks just like a new build house, fully insulated. We got AC as we have a south facing garden (although actually all our glazing on north elevation) and because we wanted heating and cooling and to be able to find tune the temperature.

Best bit is of below a certain size 30sqm, and height 2.5m (unless you dig down in which case you can add that depth to the height) no planning permission needed. Building regs may still need to be complied with depending how close to boundaries. Of course can go bigger and taller if happy to pursue planning.

Hope that’s helpful!

daisyfrau

Here are some photos. Haven’t landscaped around it yet so do excuse front. You can see the field maple next to folding doors.  

eidand

that's pretty cool, how much did it cost for everything?