This case study focuses on a basement renovation consisting of significant structural modifications which includes lowering the basement floor to increase the overall ceiling height.

1. AIMGROUP
Construction
2 8 8 3 5 N H E R K Y D R
U N I T 2 1 5
L A K E B L U F F , I L 6 0 0 4 4
T E L 3 1 2 5 6 0 2 0 0 1
E M A I L G R E G T @ A I M G R O U P L T D . C O M

2. Residential
Case Study
OUR GUIDING PRINCIPLES
 Integrity
 Best Service
 Quality First
 Safety
 On time
 Within Budget
2

3. OWNER’S REQUEST – SCOPE OF WORK
 Increase basement ceiling height from 7 feet to 10 feet
 Remove retaining wall from the middle of the basement (which
supports the house load) so there is an open and more functional
space
 Add – Kitchen, Bar room & Bathroom
 High end finishes throughout
 New mechanical, electrical, plumbing, lighting automation and fire
alarm systems
 Floor heating system
28835 North Herky Drive | Lake Bluff, Illinois 60044 | www.aimgroupltd.com | Tel 312 560 2001 3
AIMGROUP performed rehabilitation and restoration of this historical house,
which was built during the turn of the last century (1903) and less than a
quarter mile away from Lake Michigan. We maintained the home’s character
by restoring historical materials and details.
This case study focuses on the basement renovation consisting of significant
structural modifications while under an aggressive construction deadline.
Back of house
Overview of Work

4. Historical House
 Built during the turn of the 20th century
(1903), and in a state of considerable
disrepair and was structurally
compromised
Proximity to Ground Water Table
 House is located less than half a mile
away from Lake Michigan
 Existing basement ceiling height was 7
feet. To comply with owner’s required
ceiling height of 10 feet, we had to lower
the concrete basement floor slab by 3
feet which brought us close to the
ground water table
Limited Access to House and Basement
28835 North Herky Drive | Lake Bluff, Illinois 60044 | www.aimgroupltd.com | Tel 312 560 2001 4
Existing basement
Challenge

5. Structural Steel Framing
To have an open space in the basement free of any retaining
walls, we used structural steel columns and beams.
 Install temporary shoring throughout the
basement to carry the load of the existing three-
story house
 Remove retaining wall located in the middle of
the basement
 Install structural columns and “I” beams to carry
the house load
 Due to logistical and space limitations the
structural “I” beams were lowered down
from the first floor to the basement through a
temporary 24 inches wide x 50 Feet long
opening
28835 North Herky Drive | Lake Bluff, Illinois 60044 | www.aimgroupltd.com | Tel 312 560 2001 5
Sketch & Pictures showing the process
Solution

6. Sketch
Actual Picture
6
Existing basement
wall
Added basement wall
Lowered Slab
Solution - Underpinning
To achieve required ceiling height, we lowered the basement slab by three feet using underpinning method:
Excavate the perimeter foundation walls in sequence every five feet, install rebars, steel post and pour
concrete. Continue in sequence and complete the remaining perimeter foundation wall work.
28835 North Herky Drive | Lake Bluff, Illinois 60044 | www.aimgroupltd.com | Tel 312 560 2001

7.  Excavation under the existing exterior wall foundation footing
 Install posts and rebars
28835 North Herky Drive | Lake Bluff, Illinois 60044 | www.aimgroupltd.com | Tel 312 560 2001 7
 Framing and pouring of concrete
 Sequence of work: Complete underpinning installation cycle for
five leaner feet at a time and then start subsequent five feet
These images show the underpinning process.
Solution - Underpinning

8. Temporary shoring was necessary on 3 floors + Basement Due to access limitation to the basement level. The “I” beam is ready
to be lowered to the basement through a cut opening on the first
floor
28835 North Herky Drive | Lake Bluff, Illinois 60044 | www.aimgroupltd.com | Tel 312 560 2001 8
Shoring Structural “I” beam
Solution – Temporary Shoring

9.  This project was awarded the 2019:
“Preservation & Design Award” – Category Sensitive
Addition & Alteration
 Renovated basement with
 10 feet clear ceiling height
 open space without any columns
 kitchen / Bar room
 Bathroom
 High end millwork and finishes through out
 Air conditioning and heating ( chilled and hot
water system)
 Advanced fire alarm & Lighting automation
system
 Hydrant floor heating on every floor
including basement slab
 Project was completed on time and within budget
28835 North Herky Drive | Lake Bluff, Illinois 60044 | www.aimgroupltd.com | Tel 312 560 2001 9
Basement Kitchen & Bar Room
Results

10. 28835 North Herky Drive | Lake Bluff, Illinois 60044 | www.aimgroupltd.com | Tel 312 560 2001 10
Before
After

11. Thank You
AIM GROUP CONSTRUCTION MGT LTD
28835 N Herky Dr.
Unit 215
Lake Bluff, IL 60044
Tel 847 735 1904
www.aimgroupltd.com
Contact:
Greg Tchamitchian
Tel 312 560 2001
Gregt@aimgroupltd.com