We think this PVC patio door is past it’s best, I think it is 20 years old so we are considering replacing it, it is very leaky and the frame is cracking. All the current windows are PVC and are an oak colour, so I feel like we have to get another PVC window of the same finish, we aren’t planning on replacing other windows yet. But is PVC now considered a bad choice? I guess PVC windows don’t last that long. What other options would be available and what should be done for the installation? I was thinking that the internal plaster needs removing, cap off the cavity and fit insulated plasterboard. There is a steel lintel so I assume this is a thermal bridge so I think that should be insulated internally. Also I have seen tape being mentioned, is this to improve the seal? I have attached some photos of the door below.
The first two photos show damp in the walls each side of the door. Whether that is leakage or cold bridging I can’t tell. At the very least the door and frame need resealing but, yes, it ought to be replaced and fitted properly using airtight seals.
The environmental impact of PVC windows is worse than timber windows from managed forests, mainly because PVC is made from oil. But decent timber windows may be too expensive for you. The main thing is to ensure that the old window goes for recycling rather than landfill/burning.
Yes, tapes are for airtightness.
Top brands offer aluminium faced timber to give a weatherproof and hardened outer finish.
Are there any UK brands that offer the timber frame with aluminium facing? I have seen mention of european manufacturers like Velfac.
As a side note we have Velux windows and these follow that type of construction.
Velfac and Rationel Windows are Danish
Internorm are Austrian
Munster Joinery are Irish
Drumroll … 
Uni Windows are Scottish (as far as I can tell).
Hi again is there an easy way of finding suitable installers? I have read that the quality of installation is critical. Another point of reference is the Guy Martin channel 4 program, they were using lasers and airbags to get the installation correct.
I read that Guy Martin’s program cut a load of how/why interviews and demonstrations for a mass appeal. It’s a shame that a full length version or a cutting room floor compilation aren’t available somewhere.
For long life and ensuring that all seals remain intact the corners need to remain right angles. Most homes, even modern ones are not 100.00% square and so conscientious fitters pad out the base level with spacers. One problem with the normal method is that during the levelling process the frame is jacked up at the lower end by leverage. This can damage the frame. This is where the air bags come in. So I understand the theory but I have no idea where you find someone to do the job.
The first place I would look for suitable fitters is the Passivhaus Trust’s certified tradesman register. However it may not be worth quite such a high level of fitting if you don’t go for certified hardware. In either case complete airtightness is a must.
Thanks for your reply, it sounds like the Guy Martin program could have been more informative, maybe it should have an extra episode?
Is the website for the register on Member Directory • Passivhaus Trust I am struggling to find anybody that covers my area other than architects for building a complete house. I am trying an enquiry with Munster Joinery to see if they have contacts for installers. We are getting some quotes for normal windows in the next week or so, is there anything I should ask for? Or am I best to be patient and try and find a certified installer? I am conscious of just changing the window with the old methods and we still have issues with damp and mould.
Try
I selected tradesman category and windows for type
Thank you for your help, It seems my home area (Derbyshire and East Midlands), is a passivhaus desert. I have found some businesses that can advise on retrofit, so I think that is useful. I had also contacted Munster Joinery in the hope they could give me fitters details but they are only concentrating on building site work at the moment so no refurbishment or extension work.
Am I searching correctly as I only see installers for Suffolk or Cambridge one is for rooflights. Would they cover my area for just one window?
Personally I don’t want a standard install using silicone that stops working after a few years, is there a similar directory for Enerphit? Sorry for all the questions!
EnerPHit and Passivhaus require the same qualifications, so there is only one register.
You could try the AECB. Most members are also Passivhaus trained. Personally I only took an AECB course that assisted me to plan my retrofit but that didn’t lead to any certification. I think most of their members are architects or designers but they may have preferred builders or trades to work with and be willing to share that information.