Energy Efficient And Beautiful ADUs Now Available By A Unique Collaboration

Alchemy Architects has teamed up with Plant Prefab to build a good variety of Accessory Dwelling Units (ADUs) called lighthouse LivingHomes in CA. With a large shortage of housing in this area, these units will provide much needed housing in a cost effective manner. They range in size from 310 square feet to 570 square feet with the smallest ones starting at $199,999

The lightHouse's thermal envelope, and its series of floor plans are responsive to various sites and climates distinguishing Alchemy’s lightHouse from other ADUs on the market. According to Geoffrey Warner, Principal Architect of Alchemy and weehouses, “It's a well thought-out system that provides answers with limited, but luxurious, specs. This 'luxury of fewer choices' translates to build and cost efficiencies, too. Being an Alchemy project, there is also a high value placed on craft. Exterior, unique steel elements identify lightHouses as unique: weathered steel awnings, an entrance step, laser-cut door plate, and entry beacon (every lightHouse needs a light!) serve as a kind of exterior jewelry.”

According to Steve Glenn, the founder and CEO of Plant Prefab, “Our goal is to deliver design, packaged as the lightHouse, that is attainable-to-most, and will likely become even more attainable as progress and efficiencies continue to be made. Unit build costs will vary by markets, as will the site work costs which are often a significant part of any project. The lightHouse Living Home pricing is in the mid-range for 'most housing' and the lower-range for architect-designed housing. Time will tell how it prices out throughout the country, but our goal is to deliver design that is attainable-to-most.” In regard to his collaboration, he says, “The building and lending industries have been slow to adapt to new technology. How can we leverage design to truly meet long-standing goals for aspirational, super sustainable, luxurious dwellings that are attainable for more people? Alchemy has been dedicated to the idea of the “Luxury for Less”, and is optimistic that we are getting closer to that reality.”

Because these units are being built in a modular factory, they will have all of the advantages that come with offsite construction - protection of the materials from the elements, highly professional construction, shorter construction time and so much more.

Both Plant Prefab and Alchemy have always focused on efficiency and sustainability - with these units offering the same. The ADUs will all include low flow plumbing fixtures, high efficacy LED lights, ENERGY STAR appliances, no VOC paint, tankless water heaters, lots of windows to reduce the need for interior lighting, extended solid metal awnings to reduce heat gain and protect occupants from elements at entry, rain screen cladding which assists in durability for keeping moisture away from exterior wall, fire resistant exterior sheathing and weather barrier.

Alchemy has worked with Plant Prefab on two prior projects in CA. Alchemy is well known for their numerous weeHouses, generally quite small but highly efficient. Warner says “Informed by over 15 years of design thinking around the weeHouse, the lightHouse ADU reflects an efficient use of space + materials, while providing a Big House feel in a small package build.” He says they use many of the same crafted elements that they have developed and tested over the years. The lightHouse is presented as a system with limited, but luxurious options, from a custom built-in sleeping bench to options for OX steel (oxidized) exterior awnings and more.

It is interesting to note that according to Warner, “Designing and building these houses takes almost more effort than doing 2000 square foot residences because you have to be smart and efficient with your choices. It took us 3 years to adapt and develop the lightHouse plans taking work from real weeHouse projects to make sure that we address the breadth of needs at various sites and multiple uses. Since lightHouses are compact, they are well-suited to fit into places that larger houses do not. And because of this compactness, the comfort systems can be prebuilt into the box at Plant, becoming integrated with the very low-energy building envelope.”

He says this LightHouse design is sustainable, flexible, and responsive to a variety of sites, all qualities of the weeHouse, but its square foot size is within guidelines set by most cities for ADU permitting. Due to the work they did with Plant Prefab on the prior Sebastopol lightHouse, the entire line is now virtually pre-permitted by the State of California. 

Although these units are currently available for sale in CA, they will be available in other locations in the future as Plant Prefab builds additional factories in other States.