Nobody wants to have to maintain a building more than is absolutely necessary, we all lead busy lives, so we make our garden rooms so that they need hardly any maintenance at all.
We never nail anything for a start (well perhaps a few tacks in the architraves but that is about it). So everything is screwed together and this means that if ever someone needs to add some wiring at a later date and hide it inside the wall, then they can do, simply by unscrewing the cladding and threading the wire into the wall cavity by slitting the outer insulation and taping it up airtight afterwards.
With virtually all other buildings you’d have to surface mount it on the walls in conduit, very ugly and a great pity.
The first extra room, built 13 years ago and still in my own garden, could do with a fresh coat of paint on the frames now and will get some this summer but since September last year we no longer fit timber frames or doors as default so if my first one had been fitted with pvcu instead of timber then after 13 years it wouldn’t even need that.
That is pretty good, nothing at all after 13 years.
Admittedly, it has a cedar shingle roof but we have not been able to supply them for years now, since 2008 in fact when the maximum height restriction of 2.5m for the permitted development rights came in. It’s the same for rosemary roof tiles and slates as they all have no interlock and need the same steep pitches.
Cedar shingles, etc are not actually banned, but the minimum pitch they need means the roof has to be a lot higher and this means planning permission and understandably, nobody want that hassle if they can avoid it. Take a look at our current garden office specifications.
Our felt roofs have been pretty robust, only 3 have leaked out of over 300 and each was down to 'operator error’ and easily remedied, but it is necesary to either call us to drop by when we are passing or give it another coat of "solar reflective" every 3-4 years yourself, just to make 100% sure the ultra violet never gets to the felt. If that is done it lasts for decades, indefinitely in fact, even longer than EPDM which will ultimately perish due to the ultra violet finally getting to it.
An hour every 3-4 years with a roller on a nice day is not much to ask to go over the roof.
If you wanted to, you could sand down, or get a builder to sand down and re oil the cedar every ten years. With the new Osmo sun-blocking oil and a sun-blocking factor of 12 it ought to last about ten years before it bleaches too much.
So that is about all you can expect to do in the first ten years and similarly into the future, we think that’s pretty good value garden office maintenance, don’t you?