3 Benefits of Pre-Engineered ADU Plan Sets


Since the early 2000s, accessory dwelling units (ADUs) have been growing in popularity as a way to create more affordable housing options and increase density in urban areas. While there are many ways to design and build an ADU, prefabricated or pre-engineered plan sets offer a number of benefits that can make the process simpler and faster.

Pre-Engineered ADU Plan Sets are a complete set of construction documents that are created in advance for a specific ADU Model. This includes all essential plans like floor layout measurements, interior design specifics, exterior diagrams, and the like that are already drawn up and ready to be used by a contractor.

If you’re considering adding an ADU to your property, here are some of the key benefits of using pre-engineered plan sets.

1. It Simplifies the Planning Phase

When it comes to adding an ADU to your property, there are a couple different routes you can choose from. You can either have one custom designed and built from scratch, or you can work with a builder with a pre-engineered set of plans.

If you’re looking to save some time, choosing a pre-engineered plan set is definitely a recommended method. The custom design process for an ADU typically takes about 4 months before submitting for a  permit review. Whereas, if you go with a pre-engineered plan set, this timeline can be cut down significantly.

There are a number of companies that offer pre-engineered ADU plans that can save you both time and resources –  one of which is ADU.Works. ADU.Works has a team of architects and engineers who reviews and approves  their plan sets for public offering. In addition, as a full-service ADU builder, they also provide hands-on support for homeowners during the permitting process.

Additionally, because these set plans are already complete, you’ll be able to get a better idea of exactly what you’re getting – which can be helpful in avoiding any stressful surprises down the road. The process of selecting and purchasing plans from an ADU builder would be similar to buying both a product and service altogether. This makes it easier and more straightforward, allowing you to get the plans you need without any hassle. You can be assured that your ADU will be built to California Building Code and will be safe and functional. The plans are also easy to follow, so you can be confident that your builder will be able to put the unit together without any problems.

2. It Speeds up the Processing of Permits

Pre-engineered plan sets save time by about an estimate of 6 weeks in the overall ADU construction application in comparison to custom ADU plans. Urban planners have fewer design aspects to review, avoiding some of the most time-consuming aspects of approval.

However, this doesn’t mean that the plan sets are already permits-approved right away. This just streamlines the permitting process of your ADU application making it easier for both your ADU Builder and your local government to undertake. Depending on the property’s jurisdiction, this may even reduce the permitting fee as lesser time is necessary to review your ADU Plan.

3. It Decreases The Project Cost

Pre-Engineered ADU Plans are a great way to save on costs when compared to custom design plans. Some homeowners in cities have programs approving pre-engineered designs that can save their planning and/or building department staff time by having those plans reviewed before they are put into action. The reduced workloads allow these departments to offer lower fees for approved ADU plan sets.

When working with a pre-engineered plan set, you can also avoid the expensive fees associated with hiring an architect or designer. Together with your ADU builder or general contractor, this allows you to get a more accurate cost estimate for your construction project (incl. materials, labor, etc.) – helping you budget and make sure that you’re getting the most value for your money.


By providing a complete set of plans, this takes away a lot of the guesswork allowing you to focus your attention and resources to other things. In addition, these plan sets are designed to meet all the necessary code requirements, so you can be confident that your ADU will be reliable and of high quality.

This is why having Pre-Engineered ADU Plan Sets is one of the 3 Innovative Factors that ADU.Works has. Though we build Low Cost ADUs, you can be assured that we make No Compromises on our build quality and materials. Rather, we continually strive to find innovative methods to reduce costs by making our processes as efficient as possible so we can help more homeowners in California increase their housing density and/or generate passive income.

If you’re interested in a quick but comprehensive demo, please don’t hesitate to book a consultation with us or give us a quick call through our number +1 (650) 227-4810. Our team looks forward to hearing from you.

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