An Ambitious Plan for 800 sq ft House
An 800 sq ft house can be a main house, a.k.a. a starter home, or an accessory dwelling unit.
Plans for 800 sq ft houses come in many layouts. Most prefabs will be I shaped or L shaped and 12-14 feet wide. You can maximize your backyard potential with a custom shape.
What ADU floor plan will make the most of your backyard?
Hint: the ones that fit your backyard like a lost piece of a puzzle.
When planning an 800-square-foot ADU in California, there are several exciting concepts to keep in mind:
- Statewide Minimum Size: California law mandates that no local government can impose an ADU size limit smaller than 800 square feet. If it fits in the backyard of your single-family house, you can build it.
- Setbacks and Lot Coverage: The standard side and rear setbacks are 4 feet from the property line. Check local regulations for additional requirements from the Fire department when building close to fences or other structures.
- Height Restrictions: The maximum height for a single-story detached ADU is typically 16 feet. Even this height allows us to add lofts for storage or study. However, if you’re within a half-mile of public transit, this can increase to 18 feet.
- Unexpected size restriction: If the ADU is attached to the primary residence, it can’t exceed 50% of the floor area of the main home, but detached ADUs can be up to 800 square feet, even if this exceeds 50%.
- Location: Your 800-square-foot ADU is protected by state law. Local jurisdictions may allow you to place it even in the front yard if there is no space in the backyard. Have the HCD handbook ready when you venture to talk to the planner.
Case study: 2 bedroom ADU Floor Plan for 800sq ft house
One of our L shape ADU plans: 800 sq ft with 2 bathrooms
Requirements
With the future plans to rebuild the main house, our brief read that we need to maximize the size of the ADU. This meant plan for 800 sq ft house as the current main house was 1100 sq ft, and its size restricted the size of the ADU.
- Wheelchair access
- 2 bedrooms and 2 bathrooms
- Lots of windows for ventilation
- Maximizing the size
Restrictions
The location of this ADU was squeezed from all 4 sides sides:
1. Side property lines on two sides 2. Main house and 6 feet fire separation 3. Five feet Public Utility Easement at the rear property line
The client’s mother is using a wheelchair, so one bedroom, one bathroom and common living areas have to be wheelchair accessible.
The main house is just 1100 sq ft, so 800 square feet became the square footage limit.
Permit received
Result
Both bathrooms accommodate the necessary area for a wheelchair turnaround, one has a shower and the other – a tub.
In the primary bedroom the bed is positioned in front on of the TV with windows on both sides and above the bed for good ventilation.
There is a dedicated laundry space with a linen closet opposite.
The best ADU Floor Plan meets all family needs and reflects the shape of your main house and property line. Your new ADU should look like it has always been there. It should also maximize the space – take as much of your backyard as you are willing to dedicate to the new living area.
Technically, the house this size won’t even be considered a tiny home. It may fit either a young family with a kid or a retiree (or two). One of the bedrooms can double up as a home office or guest house.
Whichever ADU floor plan you select, you will not pass a final inspection without these features
Essentials for any of our plans for 800 sq ft house
Insulation
Type of insulation is called out in your Title 24 report provided by your energy consultant or HERS rater.
Kitchen Appliances
All ADU floor plans should show sink, cooktop, hood and fridge. These items are essential for anyone living permanently in the ADU.
Fire and CO2 Alarm
Smoke and carbon monoxide alarms are required on the wall or ceiling outside of each sleeping area.
HVAC and Ventilation
Ductless mini splits are an accepted way to heat and cool your ADU. Energy Recovery Ventilators are an energy-efficient way to maintain indoor air quality.
Water Heater (Heat Pump)
As California goes all electric, think about the sizing of your pump – it depends on the number of people living in the ADU.
Address Numbers
ADUs are often required to have two sets of a minimum of 4 inch high house numbers – with one on ADU and an extra that is seen from the public road. Ideally they should be hardwired and illuminated.
Consider what fits best in your backyard - we can adjust shape and size as necessary
Popular Plans for ~800 sq ft houses
ADU floor plan 720 sq ft
This two bedroom two bathroom ADU design makes efficient use of space with equal emphasis on private quarters and on common living area.
ADU floor plan 791 sq ft
This two bedroom one bathroom ADU design has a comfortable living area, two minimalist bedrooms, spacious kitchen area and a bathroom with the shower.
ADU floor plan 790 sq ft
This one bedroom one bathroom ADU has a primary en suite bathroom and walk in closet. There is room by the entry for the laundry area. The living and dining areas are comfortable sized.
ADU floor plan 770 sq ft
This detached two bedroom two bathroom ADU has a primary en suite bathroom and an additional bathroom with access from the living area.
ADU floor plan 740 sq ft
This two bedroom two bathroom ADU has a primary en suite bathroom and an additional bathroom with access from the living area. The kitchen has an option to be a separate room.
ADU floor plan 800 sq ft
This two bedroom one bathroom ADU has a luxurious bathroom with access from the living area, a walk in closet in the primary bedroom and space for the stacked washer and drier.
What plan for 800 sq ft house suits your needs most?
Try a 800 sq ft House in Augmented Reality - Right Now in Your Backyard.
Do you like one of our plans for 800 sq ft house?
Here is how we help to get started
Create property site plan
Let us answer three questions together: 1. How big can you build? 2. How much of a backyard can you dedicate to new living space? 3. How much can you afford to spend on construction.
Select the best 800 sq ft ADU floor plan
We do not like to invent wheels or bicycles. Let us get started with the plan that fits most of your requirements and then tweak it to make it shine in your backyard.
Assign the team
The success of a construction project hinges on how well the team communicates. You have a contractor you like? Bring her on board. We are happy to support you with the design, engineering and construction – when needed.
Gather Necessary Documents
Let us start with the best information available. What do you already have? Title report. Floor plan or site plan of your main house. Survey. Soil report. All these documents are a great foundation for your future successful construction project. Pun intended.
Compile the permit plan set
The number of pages in your plan set can differ from 8 to 140 (no kidding). It all depends on property specifics and city (or county) requirements. The better prepared your first submission is, the faster you get your permits.
Respond to Plan Checker comments
Do you know that the most frequent reason it takes such a long time to pull permits is the number of weeks that passed between the day the city had given plan check comments and the day your team responded to them?
Three pillars of a well designed plan for 800 sq ft house
What you need to consider for your 800 sq ft house?
Foundation
From traditional slab and pier options to hybrid foundations that use helical screw piles – the final choice needs to be evaluated on the basis of backyard access, feasibility, budget and house designs.
Performance
California is going all electric. This means your water heater will be electric. So will your HVAC heat pump and cooktop. You will be required to put some solar panels on the roof as well. All this needs a 200A + electric panel.
Natural Light
We love indoor-outdoor seamless flow and having lots of natural light. It often comes at the expense of energy efficiency. You can compensate for it with better quality windows with a lower U factor.