TFG Companies


SIP Panel Installation

Enercept, started as a subsidiary of Energy Concept in 1981, with the vision of crafting a future in manufacturing structural insulated panels, founder Harold Henley dared it all. By 1982, Enercept was incorporated and built a huge, 26,000 sq. ft. facility of its own design and products in Watertown, SD. Enercept has been manufacturing SIPs since 1981.

Enercept designs custom Structural Insulated Panels (SIPs) to exactly fit your timber frame. Whether you're building a full timber frame or a hybrid (partial timber frame), enclosing timber frames with SIPs is the perfect fit for your project. Our SIPs are high performance building panels made with an expanded polystyrene (EPS) rigid foam core sandwiched between two structural skins of 7/16" oriented strand board (OSB) used in floors, walls and roofs.  Enercepts standard 6" SIP wall has an R-24.87 value and we additionally offer R-40 or R-50 panels for your roof.  Each and every panel is custom manufactured to fit on your timber frame. Each panel comes with our standard features including: 

  • Enercept installs electrical chases at the factory and has developed an easy to follow electrical guide for your electrician.
  • Enercept factory-installs electrical wiring in our SIP roof panels (when allowed by local code).
  • Enercept’s unique 4-foot line panel press can accommodate panel core thickness from 1″ to 16″.
  • Enercept is known in the SIP industry for our ability to produce panels for even the most difficult designs. We employ an experienced drafting team to assist you with SIP design questions.
  • Enercept can provide an on-site training technician for first-time builders to ensure quality construction and minimize the learning curve. A detailed Construction Guide, Electrical Guide and durable panel layouts are issued with every project.
  • Not only have we been in business for over 30 years, we were also the original holders of the patents for our insulated connecting posts, which virtually eliminate thermal bridging, Our patented design means faster, easier, stronger construction.

Enercept panels have been used internationally with projects in Antarctica, Spain, Japan, Switzerland, France, Mexico and Canada. The largest project being the recently completed International Science Station located at the South Pole. 

In 2012 Enercept added an 8’wide (jumbo) panel line.

Enercept is a proud member of The Structural Insulated Panel Association (SIPA), the National Association of Home Builders (NAHB) and the Timber Framers Guild


"I've been using Enercept panels for the roof and gables of the log homes I build for many years. The people at Enercept are friendly, knowledgeable and always helpful. The panels are amazingly easy and fast to assemble because they come completely fabricated. The window openings and complex roof angle cuts are done at the factory - we don't have to cut any panels on site, they just slip together." Mike S.

"I would rate the insulation qualities of our Enercept home 100% better than any other house we have lived in. Even the floors in the basement, which are constructed of Enercept panels, are warm to the touch, even with the coldest temperatures outside. One of the major factors in deciding to build an Enercept home was the energy efficiency. After living in our home over the winter, I can say with certainty that the decision was a very wise one. 
I would recommend building an Enercept home to anyone that asks me." L Andera​

"Delivery was coordinated in a very thoughtful way to reduce costs and worked out beyond what one would normally expect. The panels were constructed very well and were precise. Thanks for the opportunity of dealing with a great company!"
Dave K.​


  • Structures made with our panels are compatible with Leadership in Energy & Environmental Design (LEED) certification and the ENERGY STAR rating.
  • Enercept produces the most fully customized panels on the market with all rough openings bucked out and pre-wired roof panels.
  • Our SIPs contain no chlorofluorocarbon (CFCs) or urea-formaldehyde (UF).


3100 9th Ave. SE
Watertown, SD 57201
United States

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