Masonry leaf with new timber self build

[davidc]

I am intending to build a timber frame (or SIP) house in Scotland. I had intended to clad with timber also but I am struggling to understand why some lenders (main mortgage market that is not self-build mortgage market) insist on having a masonry leaf between the frame and cladding for lending purposes.

 

Are there any fundamental reasons why a build lacking the masonry leaf would end up worth a lesser amount than the same one with it ?

 

The only argument I have found so far is that it may take longer for a lender to off load a repossessed property composed only of timber structure and cladding. But this itself must surely be grounded on some tangible/empirical reason ? So, aside from some lending reluctance, are there any cons that I have not foreseen in forgoing the masonry leaf ?

[lizzie]

Is that particular to Scotland?  I dont have a masonry leaf between my tf walls and cladding.

[Thedreamer]

The traditional practise in Scotland if building with a timber frame is once the structure is erected a single layer of blockwork goes up and this then has render applied. This is because of the wild weather we have in Scotland.

 

Our build on Skye has a mixture of blockwork and timber cladding. 

 

Seems a bit of a outdated approach by the bank as a lot of self builds are 100% timber clad or use alternative methods as the exterior skin.

 

Unfortunately the number of lenders are limited in Scotland and less for the Highlands and Islands.

[davidc]

Hi Lizzie, i got the impression that the reluctance was nationwide. There was no suggestion that mortgage lending wasn't forthcoming but just that a sizeable proportion of lenders excluded full timber without masonry. That said though, as Thedreamer pointed out, the number of lenders is less in Scotland so the effect may be even more noticeable (i'm located in the Cairngorms). So would that suggest there is an impression that timber only is less impervious to water ingress ?

 

 

Edited April 29, 2019 by davidc
typo

[lizzie]

12 minutes ago, davidc said:

So would that suggest there is an impression that timber only is less impervious to water ingress ?

I hope not! My cladding is mainly on the exposed western elevation, I’m on top of a ridge and the wind and rain can be brutal.  Hopefully not as bad as the Cairngorms though :-))

[davidc]

Quite ! Perhaps though what the lenders perceive as a risk may be in fact be somewhat illusory and just born of them being risk averse ? You'd hope above all else that compliance with the building regs/warrant system would leave any build impervious to weather for as long as is required - all other things being equal.

 

As i'm just about to decide on which way to go it would be nice to get some more clarity on the issue than i have right now though.

[K78]

I remember speaking to a self build mortgage advisor in Scotland a few years back. 

 

She was amazed I was considering TF without brick or block, and said it would not be mortgageable. 

[dpmiller]

Local lore is that anything timber-only is looked on as a prefab and so non-permanent. Hence timber holiday shacks on the coast were never mortgageable.

[davidc]

I'm starting to think there may be no demonstrable reason why not having a masonry leaf would lead to a build that has a shorter lifespan or is in some way compromised.

[Jeremy Harris]

There's no masonry in our build at all, it's timber frame with a timber cladding.  No problem with a self-build mortgage from Ecology, they didn't question it.  No problem with insurance, either, the premium's the same as if it were block and brick.

[Tony99]

We were looking at timber cladding with a small amount of brickwork for aesthetic purposes, on timber frame build and were told by Buildstore that it would significantly limit our mortgage options to just a handful of lenders. They were particularly interested in exactly what percentage of the build would be timber clad vs. brick. The explanation seemed to be that if the mortgage company had to reposses the house it would be difficult for them to sell on (as people would find it difficult to get a mortgage on a house that is timber on timber because mortgage lenders don't like to lend on these houses!). I know-proper Catch 22. We are know looking at increasing the amount of brick-partly to try and help with the mortgage situation but also we quite like the brick look! There does seem to be any major reason structurally with timber cladding on timber frame.

Having said all that, Buildstore seem to have gone very quiet recently and I am losing faith in them! I have heard good things about Ecology (as above comments) though....

[K78]

Resale is also something to consider. 

 

A lot of potential buyers would be put off by all timber construction.

 

When I first started looking at options I thought timber frame was the way to go. I didn’t realise that most of the cheap quotes with for uninuslated, 140mm frames. 

 

I don’t understand the logic in paying £25k for a uninsulated frame that needs to be insulated and clad. 

 

MBC or similar are completely different but out of my price range. 

[Thedreamer]

20 minutes ago, K78 said:

Resale is also something to consider. 

 

A lot of potential buyers would be put off by all timber construction.

 

When I first started looking at options I thought timber frame was the way to go. I didn’t realise that most of the cheap quotes with for uninuslated, 140mm frames. 

 

I don’t understand the logic in paying £25k for a uninsulated frame that needs to be insulated and clad. 

 

MBC or similar are completely different but out of my price range. 

 

I would be surprised if people were put off timber frame properties, prehaps it depends on where your based. In Scotland where the original poster is based it has always been a popular option, in our area it would be odd if a house is now build out of double block.

 

I don't understated the logic in buying a uninsulated frame, either you buy one with insulation fitted or you have a team of joiners stick build the frame on site and fit insulation later.

 

 

 

[K78]

3 minutes ago, Thedreamer said:

 

I would be surprised if people were put off timber frame properties, prehaps it depends on where your based. In Scotland where the original poster is based it has always been a popular option, in our area it would be odd if a house is now build out of double block.

 

I don't understated the logic in buying a uninsulated frame, either you buy one with insulation fitted or you have a team of joiners stick build the frame on site and fit insulation later.

 

 

 

 I didn’t mean timber frame. 

 

I meant timber frame with timber cladding. 

 

I wouldn’t personally have a issue. But surveyors would raise it on a valuation and it could put some off. 

 

Most large scale builders are using block cavity for houses local to me. Apartments all seem to be steelframe with sips. 

Edited April 14, 2019 by K78

[Thedreamer]

6 minutes ago, K78 said:

 I didn’t mean timber frame. 

 

I meant timber frame with timber cladding. 

 

I wouldn’t personally have a issue. But surveyors would raise it on a valuation and it could put some off. 

 

Most large scale builders are using block cavity for houses local to me. Apartments all seem to be steelframe with sips. 

 

The most popular new builds on Skye are r-houses. These are mostly timber frame with timber cladding.

 

https://www.ruralhouse.co.uk/

 

These are popular with self builders, families getting on the property ladder and social housing. 

[K78]

25 minutes ago, Thedreamer said:

 

The most popular new builds on Skye are r-houses. These are mostly timber frame with timber cladding.

 

https://www.ruralhouse.co.uk/

 

These are popular with self builders, families getting on the property ladder and social housing. 

 

I love Hebridean homes designs.

 

Skye is beautiful 

[Thedreamer]

1 minute ago, K78 said:

 

I love Hebridean homes designs.

 

Skye is beautiful 

 

Quite a few on the island of these as well. Monitored both when we first considered building, but prices have increased as they have become more popular.

[Gone West]

2 hours ago, Tony99 said:

We were looking at timber cladding with a small amount of brickwork for aesthetic purposes, on timber frame build and were told by Buildstore that it would significantly limit our mortgage options to just a handful of lenders. They were particularly interested in exactly what percentage of the build would be timber clad vs. brick.

We have built a timber frame with timber clad house and used brick slips for the plinth. It will be interesting when we come to sell it whether they think the brick slips are real bricks.

[davidc]

Thanks. So would having a 100mm relatively lightweight block work leaf inserted between cladding and timber frame aid the decrement delay appreciably ?

[Mr Punter]

3 minutes ago, davidc said:

Thanks. So would having a 100mm relatively lightweight block work leaf inserted between cladding and timber frame aid the decrement delay appreciably ?

 

Normally there is a gap between the timber frame and the cladding or outer leaf ventilated to outside, so the lightweight blocks would make almost no difference to the thermal performance.

[davidc]

Thank you all.

 

Regarding the decrement delay question I had assumed that part of the overheating problem and hence delay issue was due to (solar) radiation rather than thermal conduction - that is why I thought the isolated blockwork leaf may have made a difference for the walls at least in that regards. Looking at some older posts on here it seems I might not have been alone in that (possibly flawed) thinking.