Renovation Project Estimating

June 26, 2023

Renovation project estimating is quite different from estimating a ground-up project. The most obvious difference is that renovations involve existing buildings, which already include walls, flooring, concrete slabs, roofs, and most importantly - existing electrical installations! Before venturing into a renovation estimating project, you'll want to learn as much as you can about the existing building. Let's discuss a few points you should be sure to cover.


Here's a few questions you'll want to ask about the walls involved in the plan:

  • What are the existing wall types?
  • Which walls will be demolished, and which ones will remain?
  • Will this project involve removing the existing coverings?
  • If so, who is responsible for cutting, repairing, patching, and painting the coverings?


All of these questions you asked about the walls should also be asked about the ceilings. When asking about the ceilings, here's a few questions to throw out:

  • What is the plan for each ceiling?
  • If the ceilings are T-bar ceilings or glued-on tiles, how will the tiles be removed or replaced?
  • Are there any damaged tiles? If so, who will replace or repair them?

Concrete Slabs

Concrete slabs are another considerable renovation expense. Here's a few questions you'll want to ask:

  • Who will be cutting, removing, replacing, and/or repairing the slabs?
  • Who is responsible for the concrete drilling?
  • Will x-rays need to be performed on slabs prior to cutting?
  • Since X-raying can cost upwards of $150+ per location, how many locations are we looking at for the entire project?

Additional Scope

You will also want to find out if your company can be exempt from any nonelectrical scope aspects of the project. If your company is bidding as a prime contractor or the general contractor (GC) for the renovation, it might not be possible to exclude any responsibilities; in fact, you may be in charge of hiring subcontractors to fulfill various nonelectrical scope items. Dropping last-minute surprises on your GC means your company is stuck without the time to re-price the work that was left out. Excluding nonelectrical items is usually permitted by most GC's, but it is highly recommended that you communicate clearly and confirm these exclusions in detail prior to the bid. Providing a detailed summary of exclusions and quantities will keep your GC in the loop about the required scope and help them determine a price. Determining which electrical systems should remain post-renovation and be integrated into the new design is an important part of your job. This involves carefully studying any electrical demolition drawings while comparing them to the new design.

But what if there are no drawings? It's not uncommon for the engineer to not provide any drawings, or at least not sufficient drawings. Many times, the details about existing systems and the scope is in the form of inexact notes and other various documents that list basic descriptions of the existing items and the plan to perform the renovation.

Another consideration is whether you will be able to reuse existing conduits or if it will be easier and perhaps more cost-effective to install new conduits. New installations are anything but easy. Some new conduits are installed in ceilings and walls, and some are installed in a new space altogether. This part of the job can be estimated the same as any other project. However, once conduits enter existing spaces, this becomes a more difficult installation that may require a labor cost. Do you plan to isolate these installations and price them separately or work the percentage of the installation cost into your overall labor costs?

Warranty is another critical issue to take into consideration. Here's a few things to square away:

  • Who will be responsible for covering warranty on any existing electrical systems?
  • If your company is not going to touch them, who will be responsible for securing and testing them?
  • If the electrical systems were not originally built to code or the code has changed since installation, can your company exclude responsibility for these systems?

The Proposal Letter

Possibly the most crucial aspect of your estimate is your proposal letter. Communicating what is included and excluded in your scope of the renovation as concisely as possible will assure that everyone on all sides is clear on what part of the renovation will and will not be performed by your company, including warranty.

Renovation jobs are generally more time-consuming to estimate when compared with brand new projects, so a careful approach is wise. Each and every note regarding demolition, existing systems, and new installation should be read thoroughly and compared to the new plans. It's a good idea to make two separate site visits - one before starting your estimate and another visit after completing the estimate but before bidding. Even if you aren't able to survey everything - which you probably won't - you'll always be better off acquiring as much knowledge about the existing building before you bid. Always remember that an electrical contractor is responsible for a fully operable electrical system whether it is specified or not. That means this mega-checklist is on you! Be sure to cover it so you can bid appropriately.

Charter Estimating is a professional electrical and pre-construction estimating company that offers long term and short-term estimating solutions for contractors around the nation. Whether you are looking for part-time, full-time, or more than one estimator, we are always here to help you further your company’s goals. Get in touch with us today!

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