Allie Mackinnon and Charlotte Qureshi enjoy materials that are sustainable, bold and colourful and think outside the (pure white) box.


Nimtim Architects moved to an old mews stable house in London’s East Dulwich around four years ago, having decamped from a smaller workspace in the home of practice founders Nimi Attanayake and Tim O’Callaghan in Forest Hill. The practice originally rented out the ground floor to an interior designer and landscape architect but has recently taken over both levels to create a consultation space for clients.

The team of eight – plus spaniel Corbi – work from the upper floor, while the meeting space and sample storage occupy the ground level. Small samples are filed away in candy-hued HAY crates, while larger samples and reference books sit loose on the shelf. The practice has a focus on elevating everyday materials like plaster, plywood and blockwork, using more refined versions that suit their clients’ aesthetics – and budget.

The studio’s four project runners take responsibility for managing the material library, sourcing and cataloguing samples, and taking inspiration from each other’s call-ins. Project runners Allie Mackinnon and Charlotte Qureshi talk us through the process.


How do you organise your samples?

Allie Mackinnon When we moved office we had to rethink how we were keeping our library, but I think we have a good system now. We’ve got these really cute HAY crates where we’ve tried to categorise all the samples with labels – encaustic tiles, concrete worktops, gloss and matt ceramic tiles, terrazzo. We try to be quite strict with putting everything back in the right crate.

How do you research new materials?

Allie Mackinnon Everybody’s always doing independent research into materials, because the projects we’re working on are completely different. We’re juggling a number of projects that are at different stages. That means we’re gathering materials at different times. It’s quite fluid in that we’re seeing all these new materials arrive when we aren’t working on that project ourselves.

In more normal times, we got very excited about sending in CPDs, going to workshops and visiting showrooms. We went to design fairs but most of it was done just through what we were seeing every day, sometimes on Instagram.

Charlotte Qureshi We’re quite sustainably minded. Recently we’ve been looking at the embodied CO2 of different materials and we have on our noticeboard a hierarchy of materials that have the most embodied carbon and the ones with the least – and some that are even carbon negative. That’s been quite useful as a reference point when we’re starting to think about materials.


Mortise Concrete used in three of the practice’s projects: Block House, Hive House and Cloister Corner. “More recently we’re using materials for what they are and not treating them, so keeping them exposed. It creates quite a nice textural palette where the colours are quite muted but the texture brings this richness to it.”

What’s your approach to a project? When do materials become a focus?

Allie Mackinnon In the early stages, it’s knowing that an external form lends itself to a type of material – say plaster as opposed to the pattern of a brick bond. It’s not necessarily knowing at that stage what colour the plaster is but that this is the type of material that would work well. Internally, you might think that a sheet flooring could work well over a tiled floor, but without going into the colours or proportions.

There’s quite a strong dialogue between your projects. Do you find yourself returning to particular materials?

Charlotte Qureshi I think Nimtim does have a style the clients approach us for, so that seeps through. I’ve gone to the briefing meetings with clients where there’s been an theme of “one of our neighbours has this architectural white box, and we definitely don’t want that”. There’s a softness quite often to what we do. It’s less imposing.

Allie Mackinnon I definitely think there’s a common thread – we use a lot of colour and that’s maybe also because a lot of clients come with a very tight budget, and that influences what materials we would specify. They are often surprised at the innovative, colourful, and bold choices that you can make that aren’t necessarily expensive.

We’ve really tried to curate our material library so that it’s affordable and also so you can get a good quality finish that is quite architecturally interesting as well.


“These tiles, called DTILE, are really lovely because they go around corners. We used these recently on our Fruit Box project and they wrapped down to form the sink.”

Is there a virtual archive?

Charlotte Qureshi We keep a spreadsheet of materials that we’re interested in, and to keep a track of what physical samples we have – but it’s always nice to have a physical sample. Lately it’s been harder to convey that to the client when you can’t see something tangibly.

Allie Mackinnon It’s a combination of putting together a digital palette but then actually getting physical samples in and realising that it’s not quite right or this colour is actually a lot brighter than we thought. It’s always worth waiting to see what they actually look like in real life.


The practice is moving towards more sustainable materials, with a consciousness about embodied CO2. It is keen to use materials like Richlite, a durable surface made from recycled paper, but has yet to specify the products in a projects. “When it’s finished it can be used or work surfaces. It’s quite durable and hard but it;’s got a nice softness to it.”

How difficult has it been working remotely and not being able to show samples in person so easily?

Allie Mackinnon It has been a bit tricky, but we have popped in on occasion to pick up samples and hand them over to clients because I think that’s quite important to do that.

I’ve had deliveries to my home – l have roof tile samples that I’ve stored in my bedroom. It’s difficult but it’s still happening in a different way.

Charlotte Qureshi I find sometimes these days I’ve been ordering two sets – one to me and one to the client – and having discussions about the qualities.


Forticrete, used in Pitch Perfect and Yellow House. “Forticrete is an exposed blockwork normally used on quite a large commercial scale, but we’ve started using it on a more domestic scale. Blockwork is so standard but Forticrete offers finishes that are really something special. It’s almost like terrazzo as all the aggregate is exposed. We’ve used it on quite a few projects where we exposed it internally, and sometimes externally too.”

What happens to materials at the end of a project?

Allie Mackinnon We often lose materials because we’ve given them to clients. We’ve had to call up clients saying, actually I really need the sample back as it’s such a good sample, or it was hard to find! It is a bit strange because throughout the process you’re building up this collage next to your desk and then when the project is finished, you put it back into its box and it gets picked up by another project runner and maybe it’s not a floor finish anymore but it’s a wall finish.


Clayworks natural clay pigmented plaster used in A House and a Garden. “It feels quite soft and comes in a lot of different shades. We fine, rather than using white paint or leaving exposed plaster, it can have quite a nice effect. It comes in different roughnesses and you get some that are quite fine. It just provides that softness where white wouldn’t.”

Is there a material you have yet to use but have mentally filed away?

Allie Mackinnon I’ve been dying to try Smile Plastics – you can use it as a worktop and it looks like marble. They recycle yoghurt tubs and all sorts of plastics, and melt it down into this very beautiful swirl. It’s very cool but I haven’t been able to convince any clients to use it.


Ty-Mawr Cork Facade boards used in Cork House. ” There were so many factors that influenced the decision to use cork. Instead of using expanded foam, cork could double up as something that was beautiful as a finished product but could also perform as thermal and sound insulation. Since Cork House we’ve collected quite a range of cork.”

Charlotte Qureshi Passivated zinc. It’s when zinc becomes almost rainbowy but more dull. The passivation is a sacrificial layer so when you use it externally it will weather down and erode, and it protects the steel below. But because it weathers, the effect after five years will just disappear. I quite like that idea, but when I’ve shown it to clients they’re less keen. I haven’t done enough research into the implications on the rest of the design – what effect the weathering away would have.

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