Building Blox: Week 31 – Cycle and bin stores, Dealing with variations

What we did:

  • Cycle and bin stores;
  • Variations to contract spec.

The council require dedicated spaces to store bins and in line with environmental and social policies, also require secure spaces for cycles to be stored. This week we finalised these structures which I designed to complement the landscaping. Additionally, in this post I’ll talk through variations and how these are factored into the project and you can ensure extra costs don’t demolish your budget!

Bin and cycle stores

Within my design and tender I kept the form of these fairly flexible, trying to keep costs for the contractor (and so myself) low. I previously showed you the bin stores back in week 23 but we now finished them off.

The 3 cycle stores needed to be constructed to be secure structures, each able to store at least 2 bikes, one per house. I was open to simple timber or factory-made structures such as these you may see on some London streets. The contractors instead opted to build them similarly to the bin stores out of blockwork and render them. Thick, solid wooden doors were added to keep them secure. These seemed pretty expensive, strange as this is a fixed price contract and they should be keeping costs low… A good result for me though as they work really well for storage.

Variations are inevitable

It’s inevitable some specifications, layouts, etc. will change along the way, and the process to make these changes needs to be managed well, or it can lead to disagreements and delays and big cost variations. This is why when choosing a contractor, you should always ask their references how they dealt with changes. Also, your contract should explain the process for changes – often that changes and cost implications should be agreed and recorded in writing before work is carried out as in the case with the JCT Minor Works contract I’m using. This is of course easier said than done on a fast-moving building site, particularly when contractors aren’t used to documenting and discussing details. I also found that some of the more head-strong builders find that checking with clients before doing anything feels like micro-managing, so they will do the work first, then discuss cost implications, which can easily lead to disagreements, so is something to watch out for on your own projects.

Managing variations well

When onsite and into the job, contractors will take variations as an opportunity to make more money, often saying it’s a more complicated change than you may think, so to prudently manage costs, variations should be kept to a minimum!

With structural work, I minimised extras by over-engineering and over-specifying. This may be overkill, but I thought it was a safer bet and overall thought I saved both costs and hassle. Variations can easily build up when installing fixtures and decorating as there are so many small details to consider. With experience, developers get better at effectively specifying all of these details within the original tender and also perhaps have more discipline to not make changes(!) in order to control variations and so costs.

Within your own project, it’s important to build in contingency sums, that is an extra 10% or so to cover for variations so to manage your risk and budget better. Right now I estimate I will be 5% over my contract sum, but importantly will still be within my budget of the contract sum + 10% contingency. As we’re closer to the end I’m hopeful this should remain the case!

Next week we move back inside to finish the electrical second fix, fitting the fixtures and connecting up the power supply! This is following on from the electrical ‘first fix’ back in week 19 when the wiring was installed.

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