37 Years of Experience
1976-1983 residential remodels, houses, apartment building SF Bay area
1983-1993 landslide repair, foundation repair, seismic upgrades, bridge for Chevron, demolition, grading SF Bay Area
1994-2001 commercial and residential repairs and remodels, bed and breakfast, tenant improvements, East Hawai‘i.
2001-2014 home building and remodeling, East Hawai‘i
B License granted 7/6/1976 for Hennen Building Company in California
B, C17, C43 License granted 1/26/1994 for Gene Hennen General Contractor in Hawai‘i
*(C17 excavating, grading and trenching; C43 sewer, sewer disposal, drain and pipelaying).
Hennen Building Company makes a deep commitment to be conscientious in all of its projects. The company takes the time to understand each unique situation and find ways to best utilize all building options to create building projects that ensure ultimate comfort and a long life. Below are some important items to consider when planning your next project.
Large Fixes that have Multiple Effects
A slab on grade, if the topography allows it, eliminates exterior stairs, handrails, and guardrails on lanais—always the design elements that need constant repairs or replacement.
High ceilings (or a cupola, which can be incorporated into trusses) promote climate control and better views.
Windows can be oriented to catch the trades during the day and off shore breezes at night.
Big eaves, which protect walls, doors, and windows, reduce maintenance and make it possible to use clear wood finishes and fewer water resistant details.
A single story house is preferred. It eliminates or reduces future maintenance to handrails, stairs, and guardrails, and the exposure of walls, windows, and doors to weather. It is a green building design feature in Hawai‘i.
Roof pitch is important where it rains 100 inches a year. Use a 5/12 or greater pitch to improve roof performance and create a 2/12 vaulted ceiling under it for airflow.
High ceilings (at least nine feet) improve cooling and make larger window sizes possible, which also improves air circulation.
Large eaves protect exterior elements.
Make a site plan to provide for the future.
Small Design Touches to Consider
Add a water feature: an outdoor shower, a fishpond
Add an "art wall," statuary niche, coffered ceiling
Increase lanai sizes. In our climate you will use it. Tile or stain the concrete.
Close soffits to reduce mildew and future maintenance
Use some local woods
Things to Think About When Building in East Hawai‘i
Why does a typical owner/builder home take two years or more to build, and a home we build four to nine months, depending on the size? We develop a schedule based on the critical path method and give you a copy before starting. This gives you a means to monitor progress and a timeline for decisions about material orders.
Cost savings in the construction business comes occasionally from better ideas, but generally from better organization.
It has been customary in East Hawaii, especially in "deep soil" areas, where digging is easy, to bury "green waste" and rubbish while grading lots. Test borings can miss these locations. Anyone buying a lot should question the seller and all the neighbors about this possibility. Green waste decomposes slowly underground, contains air pockets, and causes foundation settlement and sunken driveways.
In East Hawai‘i, where it rains over ten feet in a year, water should drain away from a house in every direction, and on sloping lots, swales are necessary. Gravel driveways last longer when the rate of water flow can be slowed down by a gentle grade.
Douglas Fir lumber, which is treated, primed and painted, but otherwise left to the weather, only has a five to seven year life span in Hilo. The wind speed here rarely exceeds 19 mph, and typically is 0-14 mph. At 10 mph the angle at which rain falls is about twenty-two degrees, and at 20 mph it is about 39 degrees. A roof overhang of four feet that is 10 feet above a lanai would therefore protect a wood guardrail during 10 mph winds, and an overhang of six feet would be needed in 20 mph winds.
Green Building
Green building is achieved by a design, which will reduce current consumption and future maintenance.
In Hawaii good airflow and volume, created by high ceilings and ventilation, eliminates the need for heating and AC.
Energy for water heating and electricity can be solar or hydro.
Reduction in maintenance reduces future energy use.
