Garden Room budget estimate

[daiking]

Revised budget

Base £600 (half of cost in initial estimate as half size-ish)

12-15sq m log cabin £4000

50mm PIR floor + roof £250

Floor £300

Guttering £100

 

£5250

 

Initially electrics will be an extension lead ? but that’s prob £500 to add in the future.

[daiking]

Size concerns:

 

Want to push the width to max but difficult to survey space to work out. That sketch in the OP is indicative not 100% sure that size would fit so can’t just plonk a small square cabin in the plan
 

 

Base concerns:

 

Trees - will be close to a couple of trees at diagonal opposite corners. One tree big, one free fair size.

 

Timber - good in that reduced digging near trees but will raise the building by 150mm and already pushing the PD height limits as cabin options we like are 2.8m tall. 
 

Concrete - not looking forward to digging that area by hand due to trees and previous vegetation. 100mm x 15 Sq m so a nominal 1.5m3. Would prob need pump for readimix and way over what I could do as a first concrete base. 
 

Hoping it’s dry this weekend to have a gook look.

 

(Priority job is to take out a wonky fence post. See how big they are and whether 1m above ground will hold a 6ft panel ?)

[Bitpipe]

On 04/09/2020 at 17:32, oldkettle said:

Costco sell barrel saunas https://www.costco.co.uk/Garden-Sheds-Patio/Spas-Saunas/Saunas-Steam/c/cos_9.9.2

Come with heaters, installation optional. 

 

My landscaper is just finishing a Costco log cabin - says that the 4mx5m ones are going for about £3.5k as DIY (£5k installed). He says this is a crazy low price as he used to work for a local log cabin firm and the equivalent footprint and same quality would be £10k plus installed.

 

On a related note, a friend is asking me what regs are required to build and rent out (AirBnB) a garden room / cabin? He's up Banbury way in a nice village and they have a high demand for holiday rentals but also HS2 crew accommodation (one upside of it running within 500m of his house).

 

He has a decent sized area next to his main garden that's already naturally separated with mature hedging, connects with the main drive to his house and making power, fouls and water would be straightforward enough. He was thinking of a log cabin or similar, enough for one studio bedroom or bed / living with kitchenette and bathroom.

 

My understanding is that you first need planning permission if the dwelling is not exclusively for the enjoyment of the household (i.e. a garden room) and then the applicable BRs apply depending on whether it qualifies as a mobile dwelling or something more substantial.

 

 

 

 

[daiking]

Shuuuuuuhsh  ? but the tuin sale is on.

[daiking]

Slight problem. 
 

We would like to build a log cabin with a 17sq m floor area within 1m of the boundary. Due to the triangular boundary we just can’t get 1m clearance on both sides.

 

Should still be fine on being permitted development but what are building regs for a log cabin?

 

Is it just class 0 fire performance or are there other considerations? Insulation?? Structural considerations?

 

Will a wood treatment meet the class 0 requirement? Would a large window prevent the facing walls meeting class 0?

[Mr Punter]

Within a metre it needs to be non-combustible, so the log cabin is out.

[daiking]

3 hours ago, Mr Punter said:

Within a metre it needs to be non-combustible, so the log cabin is out.

 

I know about the 15sq m limit.

But what does non-combustible really mean? Class 0 fire resistance?

And what is the process of getting a log cabin to meet it and be checked? (Is it worth the hassle) 

[Gus Potter]

For a bit of info and to provide a bit of backgound on the fire regs as @daiking mentions... it's weighty subject but hopefully this helps.

 

I'm no JK Rowling but here goes.

 

The fire regs are commonly thought to have been introduced after the Fire of London. They realised that the fire spread not just because of the sparks and flames that jumped from building to building but that also the buildings radiated heat, like an electric fire. We know that if you put something too close to an electric fire you can set it alight even though there are no flames or sparks. This paid dividends in the Blitz, but less so elsewhere in the UK.

 

This is one principle that is recognised in the regs today. When you build close to a boundary (say 1.0m or less) you need to stop some things from happening. These are:

 

1/ You need to make sure that if your building goes on fire the flames and sparks don't jump the boundary and set light to a neigbouring property. This is called "integrity"which means that the cladding and underlying wall does not start to expand, buckle and force the cladding seems open etc, letting the flames and sparks through.

2/ You need to make sure that your wall does not heat up enough so that it radiates heat, like an electric fire, and that this radiant heat does not set light to another property, this is often called " the fire insulation" ... 1 & 2 are different properties.

3/ You need to make sure that the Fire Brigade can put out the fire without risk of (commonly, but not always) the wall collapsing on them.

 

Thus when you have a fire boundary condition you need to design the wall so that:

 

 1/ The structure (call it the skeleton) of the wall is sufficiently protected so that it will hold the cladding in place, gaps in the cladding won't open up letting flames through and so on.

2/ That the make up of the wall is insulated enough so that the wall won't radiate too much heat over the boundary. This often means you need to clad the inside of the wall with fire protective material, or directly protect the structural frame holding the cladding in place.

3/ That the actual cladding won't catch fire from the heat and same cladding won't then send sparks and flames over the boundary, hence the Class 0 cladding rating... which means that it does not catch fire.. unlike bricks which don't burn.

4/ That the fire boundary wall will stay up long enough so that the fire can be safely put out and ideally it won't collapse a bit later on on the fire investigators...  but this (in my view) needs more devlopment in the regs.. they partly address this in New Zealand etc..here's hoping it will get more attention in the UK.

 

The regs in England are a little different than those say in Scotland, but the same principles apply.

 

If you have read this far then thanks. Hopefully what I have outlined will help some to make headway with the building regs and why BC are asking the things they do.

 

In summary @daikingYou may be able to apply protective coatings to the timber to get class 0, but remember you also need to protect the structure so that the wall says up. You can find more info on the net.

 

All the best and hope you enjoy your project.

 

 

 

 

[Mr Punter]

1 hour ago, daiking said:

 

I know about the 15sq m limit.

But what does non-combustible really mean? Class 0 fire resistance?

And what is the process of getting a log cabin to meet it and be checked? (Is it worth the hassle) 

 

Why not build it and see what happens?  Unless a neighbour decides to be tricky it will be OK.  In reality you are not compromising anyone's health and safety.  It is your land.

[daiking]

8 hours ago, Mr Punter said:

 

Why not build it and see what happens?  Unless a neighbour decides to be tricky it will be OK.  In reality you are not compromising anyone's health and safety.  It is your land.

That’s quite a risk to take with an unknown outcome. I would prefer to meet my obligations and be able to tell anyone who objects to mind their own business.

[daiking]

9 hours ago, Gus Potter said:

For a bit of info and to provide a bit of backgound on the fire regs as @daiking mentions... it's weighty subject but hopefully this helps.

 

I'm no JK Rowling but here goes.

 

The fire regs are commonly thought to have been introduced after the Fire of London. They realised that the fire spread not just because of the sparks and flames that jumped from building to building but that also the buildings radiated heat, like an electric fire. We know that if you put something too close to an electric fire you can set it alight even though there are no flames or sparks. This paid dividends in the Blitz, but less so elsewhere in the UK.

 

This is one principle that is recognised in the regs today. When you build close to a boundary (say 1.0m or less) you need to stop some things from happening. These are:

 

1/ You need to make sure that if your building goes on fire the flames and sparks don't jump the boundary and set light to a neigbouring property. This is called "integrity"which means that the cladding and underlying wall does not start to expand, buckle and force the cladding seems open etc, letting the flames and sparks through.

2/ You need to make sure that your wall does not heat up enough so that it radiates heat, like an electric fire, and that this radiant heat does not set light to another property, this is often called " the fire insulation" ... 1 & 2 are different properties.

3/ You need to make sure that the Fire Brigade can put out the fire without risk of (commonly, but not always) the wall collapsing on them.

 

Thus when you have a fire boundary condition you need to design the wall so that:

 

 1/ The structure (call it the skeleton) of the wall is sufficiently protected so that it will hold the cladding in place, gaps in the cladding won't open up letting flames through and so on.

2/ That the make up of the wall is insulated enough so that the wall won't radiate too much heat over the boundary. This often means you need to clad the inside of the wall with fire protective material, or directly protect the structural frame holding the cladding in place.

3/ That the actual cladding won't catch fire from the heat and same cladding won't then send sparks and flames over the boundary, hence the Class 0 cladding rating... which means that it does not catch fire.. unlike bricks which don't burn.

4/ That the fire boundary wall will stay up long enough so that the fire can be safely put out and ideally it won't collapse a bit later on on the fire investigators...  but this (in my view) needs more devlopment in the regs.. they partly address this in New Zealand etc..here's hoping it will get more attention in the UK.

 

The regs in England are a little different than those say in Scotland, but the same principles apply.

 

If you have read this far then thanks. Hopefully what I have outlined will help some to make headway with the building regs and why BC are asking the things they do.

 

In summary @daikingYou may be able to apply protective coatings to the timber to get class 0, but remember you also need to protect the structure so that the wall says up. You can find more info on the net.

 

All the best and hope you enjoy your project.

 

 

 

 

Thanks, that’s useful to know, I was fishing here to see if anyone had experience of this issue.

 

Might just have to go back to the original proposal ?‍♂️

[daiking]

Tuin sale ends tomorrow. I think we’re going to order the smaller one that is under 15 sq m internal floor area. 
 

I am still keen to build a kit myself despite having no prior experience. The base is still up for debate for how and who will do it. Going to start a thread about the base.

Edited November 16, 2020 by daiking

[daiking]

A Tuin Lory has been ordered.

 

The existing shed has been wedged as far back as possible.

 

 

[daiking]

The log cabin is only going to be about 13sq m internal area which seems a bit of a waste. But starting to measure out it’s clear that without removing big trees or completely blocking off access, this is about as big as possible from the standard options we looked at. Ball park it’s 14’ x 11’, which is bigger than our lounge (small houses).

 

Having punted the original shed back into the far corner, there still a load of room for something behind the log cabin. Probably have a covered storage area there for furniture/gardening stuff. Or that composting toilet in the future.

[daiking]

Lory was delivered on Monday. Had to open the pallet today to move it from the drive to the garden. All 1.25 tonnes of it, one bit at a time. It is a thing of beauty. Masses of straight, machined timber. Smelled great too. Looking forward to putting it up. Not looking forward to all the work still needed to be in a position to put it up. 

[daiking]

The cabin seems fairly simple to assemble the bulk of it but the instructions are a bit sparse in a few areas. There's a lot of ambiguity regarding securing to the to base, no detailing of where to use the different fastenings and very little finish detail for this particular type of flat roof. None of it is rocket science but it would have been nice if it clearly showed the ideal finish. 

 

For example this model has a shallow angle flat roof with tall fascia boards around the cabin. Unless there are not enough roof boards to completely fill this area there's no indication as to how you should allow water to drain off the back of the roof. I shall be emailing them before I build to to confirm a few things. 

[Onoff]

Should have bought / got given a caravan!

 

I know a lad who painted his MK 3 'ish Escort in a wood grain effect...

[daiking]

1 minute ago, Onoff said:

Should have bought / got given a caravan!

 

I know a lad who painted his MK 3 'ish Escort in a wood grain effect...

 

Access is about 1900mm wide

 

 

[PeterW]

22 minutes ago, daiking said:

The cabin seems fairly simple to assemble the bulk of it but the instructions are a bit sparse in a few areas. There's a lot of ambiguity regarding securing to the to base, no detailing of where to use the different fastenings and very little finish detail for this particular type of flat roof. None of it is rocket science but it would have been nice if it clearly showed the ideal finish. 

 

For example this model has a shallow angle flat roof with tall fascia boards around the cabin. Unless there are not enough roof boards to completely fill this area there's no indication as to how you should allow water to drain off the back of the roof. I shall be emailing them before I build to to confirm a few things. 

is it a Tuin..??? Did you go with felt or rubber roof ..??

[daiking]

48 minutes ago, PeterW said:

is it a Tuin..??? Did you go with felt or rubber roof ..??

It is a Tuin and it has a felt roof.

 

Felt Shingles were a no cost upgrade but they don't seem to be worth it on this flat a roof.

 

The EPDM upgrade cost was comparable to buying the full rubber roof kit yourself so I've taken the felt no cost option. Should have enough spare to re-roof the shed the next 2 times and I'll look at doing a proper roof in a couple of years when it needs re-doing. 

 

Bar-stewards:

 

"As of the 5/2/2021, we have stopped offering free offer shingles on our Modern Log Cabins. These changes will also apply to the orders placed after the 5th of February.
To ensure our customers receive the best roofing option possible- We have now changed the options for the Modern Log Cabins. Now, pricing for the Modern log cabins include EPDM Roofing and Adhesive which is the best and most reliable roofing option we can offer, This is what we always recommend for log cabins with a pent style roof."

 

 

Edited February 16, 2021 by daiking

[PeterW]

Ok so I have first hand experience of these. They are unforgiving when it comes to the layout of the beams and you have to get them perfectly level. The roof slope is just that - a slope - and you put the boards 3 sides and either leave the lowest side off or do what I saw done on a demo unit which was to hide a gutter behind the back and run the felt into it as you have plenty of excess on the fascia boards. 

[daiking]

4 minutes ago, PeterW said:

Ok so I have first hand experience of these. They are unforgiving when it comes to the layout of the beams and you have to get them perfectly level. The roof slope is just that - a slope - and you put the boards 3 sides and either leave the lowest side off or do what I saw done on a demo unit which was to hide a gutter behind the back and run the felt into it as you have plenty of excess on the fascia boards. 

 

I have some ideas but it will be something to make up when its constructed and you sit there scratching your head going wtf? Another reason to do this in felt first.

 

The side and back have a 300mm overhang so there's room everywhere but there's a wierd 44x44mm plank detail around the inside of the fascias. I was going to ask them to confirm what the point of this was, whether it goes over/under the felt. Also detailing of how to hold the 3 fascia boards together vertically and have the board flush to the felt etc etc

 

fwiw, felt is IKO Armour Valley which is much more substantial looking than the IKO shed felt I have on the shed. 

[PeterW]

7 minutes ago, daiking said:

Also detailing of how to hold the 3 fascia boards together vertically and have the board flush to the felt etc etc

 They screw to the edge of the board and the ends of the cross beams. 

[daiking]

4 hours ago, PeterW said:

 They screw to the edge of the board and the ends of the cross beams. 

On this model the roof joists run front to back as you have a 1200mm front overhang. At the sides you add timber sections at the top of the wall to reach another 300mm. There’s a weird 44x44 piece all the way round. Presumably on a basic roof you felt under that and lap the felt down the sides and the fascia clamp it against the short joist pieces. I’m planning to insulate the outside of the roof with 50mm PIR so I’ll probably felt over the 44x44 sections and down the side. 
 

I have underestimated my insulation requirement as the easiest way to put the roof surface on is to insulate all the big overhangs as well ?

 

This still leave the detail at the rear to think about when the time comes.

 

We’re getting the tree cover trimmed back as well so may stick a hole in the roof in future for a stove.

 

[daiking]

So the insulation website I was keeping track of is having a price imcrease this week so I need to place my order although I’m not ready.

 

I looking at:

 

125mm EPS below the slab.

6 sheet 25mm @ £4 each

5 sheet 100mm @ £15 each

25mm EPS on top of the slab (with chipboard floor and engineered wood floated in top)

 

6 sheet @ £4 each

 

Roof 50mm PIR on top, under the felt.

 

This is were I made a mistake in my new budget as I had not accounted for the overhangs. 1.2m to front, 0.3m to other 3 sides.

8 sheets @  £19