11 unnecessary uses of plastic in buildings

Plastic; it's everywhere. It's become so fundamental to how society functions we don't even seem to see it anymore. Spurred on by the recent BBC documentary 'War on Plastic', I have been reflecting on some of the needless places we use plastic in the construction industry. In true Spinal Tap style, I've come up with eleven common examples. It's by no means a comprehensive list, but it does highlight how ingrained the use of plastic is.

1. Packaging

It's the same problem we have with our groceries. It seems like everything has to be wrapped in plastic these days. Even bricks - the things you build walls from and expect to tolerate the wind and rain for 40+ years - apparently have to be wrapped in plastic to protect them.

And as with our groceries, the solution is actually super simple. The manufacturers just need to stop wrapping stuff in plastic for no reason!

2. Windows and doors

Perhaps the most obvious of all of the items on my list is windows and doors. My problem with them is this: They are sold on the basis that they are a sustainable alternative because they reduce our heating bills. That's fair, but what nobody ever seems to think of is that a) they never seem to last very long and b) even if they are recycled, there is a limit to how many times plastic can be recycled, so eventually they will become landfill.

Timber and aluminium, on the other hand, are far more sustainable alternatives. Aluminium isn't perfect since it takes some energy to make it, but at least it can be recycled indefinitely, and most decent brands are quite well-made, so they should last well. If you want something really robust that can be recycled, then steel is a good option too.

3. Membranes

Ever wonder what people did 100 years ago without plastic to keep everything dry? Well, actually it's quite simple. They built their buildings so that they could 'breathe'. Admittedly, it might not have been a deliberate decision, but the natural materials our ancestors used had the capability of allowing moisture to pass through them, yet still kept them dry (like Gortex, but without the plastic!). We now label these types of materials as 'hygroscopic', and we're realising it's a much better way to manage moisture. Plastic membranes may be intended to keep moisture out, but they can also force it into other parts of the building in higher concentrations (i.e. rising damp), and they can trap condensation inside the fabric of the building causing problems with rot and mildew. These are bad things.

We can build without plastic membranes if we make our buildings hygroscopic. All it takes is a little thought about what materials and finishes to use.

4. Insulation

Polyisocyanurate (or PIR for short) is amongst the most common of insulation materials. One way or another, it gets used in almost every single building we build these days. We also seem to like polystyrene. Guess what? They contain plastic.

And yet there are so many alternatives. Some of my personal favourites are wood-fibre insulation, sheep's wool, and blown-cellulose (made from recycled paper). They're all examples of natural hygroscopic materials.

What about insulation under solid floors? We can't use any of these materials, but there are a couple of other options. One is expanded clay aggregate. When combined with a limecrete slab, this makes a great alternative to a typical concrete floor. It's most often used in historic buildings, but there's no reason it couldn't be used in a new-build too. Or you could use a foamed glass aggregate, which is made from recycled glass.

5. Construction tapes

We've started using plastic tape everywhere to try and improve airtightness. I'll admit this is a tricky one because airtightness is critical for reducing heat-loss in buildings. However, I do think there is scope to reduce the amount we use it by designing-out problem areas that would have otherwise required taping.

6. Plumbing

Plastic piping has now become extremely common in new-build situations. It's easy to fit, and extremely fast, making it inexpensive. It also suits the needs of the DIY installer.

However, copper is still a better option, in my opinion. It can be re-used and recycled indefinitely.

7. Render

Some external renders contain plastic polymers that are supposed to improve the longevity of the finish. They require virtually no maintenance.

However, they're not hygroscopic. A better option is a lime-based render. Lime renders are hygroscopic and have a low environmental impact. Granted, they require a bit more TLC, but I think it's' worth it. Lime renders are most commonly used in heritage projects, but there is absolutely no reason why they cannot be used to build something very contemporary too.

8. Ducts

Similar to plumbing, plastic ducts are cheap, easy, and quick to buy and install. Plastic also works well for ducting because it’s smooth and this improves the airflow.

The best non-plastic option is metal. It might take up a bit more space, but you don’t necessarily have to cover it up. Get creative and think about how the ducting can become part of the architecture, like in this example.

9. Cladding

Why you would want to stick sheets of plastic all over a building is beyond me, but apparently, people do. There are so many better options! You can use timber, fibre-cement, render, slate or metal. You can even use cork! There are loads of options. Just use your imagination and whatever you do, don't stick plastic on your house!

10. Gutters

Please just don't. Use metal instead. Plastic gutters may look tolerable to start with (even saying that hurts me slightly) but give it a few years and the UV light will start to make them fade and go brittle, and they'll probably sag, causing problems with drainage.

Do yourself a favour and use a sturdy metal gutter. My personal favourite is steel. If you hold some plastic gutter and then some steel gutter, you will instantly be able to feel the difference. If you buy robust guttering, it will never need to be replaced if you just give it a little TLC every now and then.

11. Flooring

Plastic laminate flooring and synthetic carpets are popular because they are inexpensive, low-maintenance and last well. However, I'd still urge you to consider the alternatives. Option 1; don't have floor finishes. Exposed concrete floors can be beautiful, and you can add a wool rug for warmth underfoot. Option 2; use natural materials like sustainably-sourced timber or cork.

Towards plastic-free buildings

I'm sure there are tonnes more places we can find plastic in our buildings, but these are the eleven most obvious I could think of. The thing is, in almost every single case, there is a non-plastic alternative. So, it really does beg the question, why do we use so much plastic in our buildings? If you’re embarking on a project, think twice about what plastics you are introducing. There’s probably a plastic-free alternative.

Let me know in the comments if you think of any other examples.