When is daylight of dream home interiors no longer useful and what are you going to do about it?
 

This custom dream home designer uses a self-made set of tools to address the extent of daylight penetration

Initially based on the two references in the daylight companion piece hereunder, we’ll use the algorithm that natural home light’s intrusion is useful to the extent of twice the distance on the horizontal as the uppermost height of the fenestration’s glazing To assess implications particularly to safety and functionality To reckon ways to remediate problem spaces

A window in a wall where the exterior of the window is unencumbered with a cover, as by a roof and the like

For example, the window glazing tops-out at about 8 linear feet above finish floor (the measurement metrics aren’t scientifically exacting and, in this custom dream home designer’s opinion, neither need the inputs); thereby, 8 linear feet x 2 = about 16 linear feet of useful, natural home light intrusion.

Applying the 2x glaze height metrics in porch and portico, let’s use a real instance –

	The lanai’s roof eaves-out above a beam furred to 8’-8”, which is the daylight-intrusion height the self-styled analysis begins
	Distance from furred beam front of face to exterior glaze of the window pair = 8’-0 7/8”

There’s nothing like this systematic, dream home daylight designing method known to the author; it was borne of a gnawing frustration with deeper and deeper homes from front to back and more and bigger porches
 

This custom dream home designer’s algorithm discounts daylight to the interiors by the fraction of distance from beam front of face to window front of face, or 8’-0 7/8” / (8’-8”x2) = 46.6%, that is, 100%-46.6% = 53.4% of natural home light’s usefulness is available to the window; finally, daylight intrusion to interiors in this example amounts to the window’s approximate glaze height above finish floor, or about 8 linear feet x 2 x 53.4%, or about 8 ½ linear feet

Now, let’s apply both the simple and the not-so-simple math to a whole level of a home’s floor plans

Darkening those areas that fall outside the extents of calculated daylight intrusion (marginally revised in subsequent version)

This visual is part of a real enterprise undertaken by Before The Architect

	Areas of general disinterest include Closets Infrequently used hallways Garage Family (centrally sited under 8-sided tray ceiling), half-shadowed, below the octagonal tray ceiling rightish, with its large entertainment center on the interior wall
	Areas of general interest include Masters bedroom on extreme left The major traffic transaction area - Center Hall - immediately to Master’s right The Kitchen – in total shadow – farther to the right, including the curvilinear island Frequently used back hallways

Masters remediation

Added perimeter windows on Left Of House wall line

Center Hall and Kitchen remediation

Bring on the Solatubes

	Rooftop ports can be hidden from Front Of House, casual observation
	Clients have no problem with their appearance anyway compared with, for example
	Skylights, to the clients and the dream home designers, are simply unattractive
	dormers, stylistically and environmentally, are out of place
	Solatube lumens, installation prescripts, illumination coverage (or, effectively beam spread), illuminance control – all enable Solatubes in this application, even in retrofit for their minorly disruptive insert
	Interior illuminance targets had already been calculated for Kitchen, Center Hall, and elsewhere in Nightlight scheduling, so they’re compared with calculated delivery in daylight-needy areas

Dream Home Daylight Design System Solatube Illuminance Schedule

Adjustment for beam spread given two sizes of Solatubes in home light of [a little pun intended, there] was required to address the difference between Solatube model distance from ceiling to floor of 8 linear feet and this custom dream home’s 10 linear feet ceiling height (the study is by Before The Architect), an excerpt of which follows –

Pictorially, interiors' illuminance appears significantly effective, whereat, the hatched areas are surfaces involved with Solatube illuminance in this Roof Plans Overlay to L1 floor plans

Closer in, this is a look-see at several of the Solatube’s interiors' extents above and one of the interiors below, this one of the leftmost in the back halls

	Take this Kitchen.  Spread to upper regions is fully to its beam spread extents; however, elsewhere, walls impede.  Note well that that this impedance is not blockage, but rather it’s redirection, that is, those walls redirect home light, they’re are brighter and reflect more.
	In other words, be careful to put daylight where you want it and, importantly, how you want it, e.g., not glaring to the eye, not reflecting off of shiny surfaces, possibly decorated on the interiors to absorb excess illuminance or, even, use it to highlight dramatically.

Kitchen (and other spaces so daylit) fared well, too, again excerpted from a Roof Overlay in plan view