How to Read Building Plans

Building plans are your best resource for understanding the home's design and ensuring that it will be built as you expect. To use them effectively, you'll need to get used to reading them. The videos below will help.

Online Event Video: Reading the Building Plans

The 23-minute video below is an excerpt from an online event that covers many of the ideas in this chapter.

The Plans

Before we dive in, it's important to note that the plans represent exactly what will get built. If there are things you want to change, do it in the plans, because there is no more affordable time to make changes.

Homeowner Darren, who used to work theater productions, described how his experience relates to home construction:


In theater, you need to design a lot of sets that will appear in the production. Those set designs happen on paper before they're built and we often said, "If it ain't on the page, it ain't on the stage". I take the same approach to house plans. The plans on the page are how you account for what will be built. If it’s not in the plans, it won’t be in the house.

Perhaps that's a mantra you can adopt when it comes to reviewing plans: if it ain't on the page, it ain't on the stage.

Below we'll cover five essential plans that you'll use in designing your home. They are:

  • Site Plan
  • Floor Plan
  • Elevations
  • Sections
  • Lighting and Electrical Plan

The Site Plan

The site plan is a two-dimensional overhead view of the property, often with lines that indicate topography and property lines. You’ll see the house’s location and how it relates to the land around it. This plan is essential in making sure that the house will be built where you want it.

Questions for the Site Plan: 

  • Is the house facing the right direction? 
  • Is the house placed on the property in the correct location?
  • Is the house the size that you want it to be? 
  • Are you accounting for how you might use the property in the future?
  • Are all existing features present in the plan? Trees, etc.?

Landscape Architect / Designer

The site plan can also be a starting point for working with a landscape architect/designer. If you plan to have a professional design the property around the structure, it's a good idea to get them involved from the beginning. While much of their work might be done after the structure is complete, there are likely key points of discussion with your architect that result in a cohesive design with the structure.

As a cost savings, site work and excavation for both the structure and landscaping may be scheduled together. There may also be materials in common that can be ordered together. For example, if the landscape architect plans to use the same decking materials attached to the house in other parts of the property, you may find cost savings in having it all managed together. Ask your architect what would work best for your project.

We’ll talk more about the site plan when we discuss the survey of the property.

The Floor Plan

The floor plan is one of the most useful and important plans. It’s an overhead view of the structure that indicates its shape. You’ll see how the house fits together and the dimensions of each room, for example. Over time, this plan may also contain icons and notes for electrical outlets, lighting, and even windows. 


Do you have important keepsakes that you want to display prominently in your home? This could be a guitar, photo, trophy, or art. It's not too soon to think about where they will live in the home. Understand their dimensions and work with your architect on specific locations. This could include an recessed section of the wall called a niche, or an alcove. Once the location is picked out, you can be sure it has good lighting, too.

Spend time poring over the floor plan because it is the clearest representation of what will be built. For example, it can be helpful in accounting for all the features you’d like the house to have, from rooms to the placement of kitchen appliances. Time spent revising the floor plan is a good investment. Expect to work with the architect on changes to the plan over the course of the project and especially early on. Always remember: changes on paper are cheap.

Questions for the Floor Plan:

  • Are all the rooms present?
  • Are the rooms the size you want?
  • Are windows and doors where you want them?
  • Is there space for the furniture you plan to use? 
  • Is the kitchen island the size you want?
  • Are the appliances in the correct locations?


Unlike overhead views, elevations are from the side, usually for each side of the house. This perspective is meant to represent a real-world view of the house as if you took a picture from the middle of one side.

This can be a useful perspective in understanding the shape of the house, like how tall it will be or what will be visible where. The elevations can also be used to document the effect of posts, design of siding, landscaping walls, and other exterior finishes.

Questions for the Elevation Plan:

  • Does the house look as you expected?
  • Does anything seem out of place, sized incorrectly, or oddly designed?
  • Does the exterior design feel balanced? 
  • Are the windows and doors the right size and in the right locations?
  • Do the windows open in the desired direction?
  • Does the slope of the roof seem correct?
  • Is the roof and siding material correct and designed correctly?
  • Does the house sit on the property/grade as you expect?


A cross-section is like an elevation of the interior. Here, the home is viewed as if the house were sliced in half and viewed from the side. This view of the interior can provide a useful look at the size and shape of the spaces and how they will feel relative to one another. Architects will often add a person to the plan to give you a sense of scale. 

  • Does the interior space look as you expected? 
  • Are the built-in furnishings the size and place you want them?
  • Does the space or volume of the room seem correct?
  • Does the slope or shape of the ceiling make sense? 

It takes a bit of experience, but understanding the basics of building plans is an important part of being an engaged homeowner. Knowing their role will give you a way to double-check what’s being built.

Lighting and Electrical Plan

You may see the plans for lighting and electrical on separate pages, or combined with the floor plan. In the video below, we'll use a combined plan.

Electrical /Outlet Plan

This plan shows the location of electrical outlets. Like the electrical plan, this documents the placement of power outlets, or “receptacles”. Your local building codes will likely require receptacles to be placed at a maximum distance apart, like 6 or 8 feet. Any other locations are up to the homeowner. You can find them in cabinets, floors, on countertops, and more. This plan also accounts for high and low-voltage needs. 

Questions for the Electrical Outlet Plan:

  • Are there enough receptacles? You can add more and might consider it for offices or garages.
  • Would you like to use receptacles with USB or ethernet outlets?
  • Do you have 220-volt receptacles for the appliances you’ll use? Electric cars? UV heaters?
  • Do you have receptacles for low voltage or outdoor lighting? What about LED strips?
  • What are the heights of your receptacles (center of box to finished floor)? Typically, there is a standard height chosen for the house overall, then you can identify special cases - under benches, floating nightstands, in cabinets, on/over countertops.
  • If you have an ethernet network, is it in the plan?

Reflected Ceiling Plan

This plan documents what you’d see if the floor of the house was a mirror. It shows the shape, dimension of the ceiling along with ceiling material and light fixtures.

This plan is sometimes combined with the lighting plan, which documents the location of built-in lights and switches. This plan is very important to read carefully, as it governs what switches control what lights.

Questions for the Reflected Ceiling:

  • Is the ceiling material in each room correct?
  • Are smoke detectors, fans, etc. where they should be? 

Questions for the Lighting Plan:

  • Are there enough lights?
  • Are the switches in the right place for the specific lights?
  • Do you have 3-ways switches? Where? 
  • Do you have deck or exterior lights?
  • Are all light circuits correct?
  • Are the switches where they should be?
  • Are there annotations for the types of lights (sconces, pendants, etc.)

Three-Way Switches

Your house is likely to include 3-way and maybe 4-way switches. These are light switches in different locations that control the same circuit of lights. This means the lights can be turned on or off from either location. Watch the video below:

3D Models

Architects have a long history of building tiny three-dimensional models of buildings that represent the finished product. These require time and skill, but are incredibly useful in getting a real sense for a building before it’s built.

Today, these real-world models are being replaced by three-dimensional computer models built with software. Many architects build these digital models before construction begins to help the owner and builder see the house from all angles and even walk through it, virtually.

The models can relate anything from walls and lights to colors, fabrics and finishes. The models are incredibly helpful and you might ask an architect about them before hiring them. There are a number of software programs that can do this work, and a popular one is SketchUp, by Trimble

Homeowners John and Lynn:


Our architect created 3d renderings of most of the house and it helped a lot to be able to see it from that perspective. Once we were close to complete, the appliances were being installed and we realized that the first thing you see when you walk in the front door is the white washer and dryer against the dark colors of the mud room. It drove us crazy and we had to change it. Looking back, the mud room was a part of the house that was not rendered in 3d. If we had a complete rendering, I think we would have caught that before the appliances and plumbing were in place.

DIY 3D Models

If you’re so inclined, it’s possible to learn 3d modeling using your home computer or iPad. SketchUp provides free versions of the software that work with any web browser. The free version of SketchUp helped build models of the Flattop house that became useful in discussing things like changes to the deck’s shape.

Get Involved

It might be tempting to see the plans as just the business of the architect and builder. And to some degree it’s true. But you, as the owner, have an opportunity to review and adjust the plans according to your needs and desires. The plans are where you can make sure your house is built for your lifestyle.

Homeowner Monique:


One thing we did not realize in our design process was the height of the ceilings will have an impact on the size of windows but also the door heights. We have 10 ft ceilings, which means non-standard door heights, which means an extra expense that we were not aware of. Plus the higher ceilings mean extra time/work/consideration for HVAC and heating systems. I did not ask for 10 ft ceilings, they were just in the plans and we went with it, not really considering the impact.

Do Research

Building plans and permits are often in the public record. This means you may be able to research the plans of buildings near you, or what previous owners did or wanted to do but couldn't. For example, if a neighbor or previous owner wanted to add a garage but couldn’t get the permit approved, this may help you choose a different path and avoid a dead-end in the permit process.

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